All upcoming events

Complexity-Theoretic Foundations of Quantum Supremacy Experiments

Date:
25
Thursday
January
2018
Colloquium
Time: 11:15-12:30
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Scott Aaronson
Organizer: Faculty of Physics
Details: 11:00 Coffee, Tea and more
Abstract: In the near future, there will likely be special-purpose quantum computers with ...In the near future, there will likely be special-purpose quantum computers with 50 or so high-quality qubits and controllable nearest-neighbor couplings. In this talk, I'll discuss general theoretical foundations for how to use such devices to demonstrate "quantum supremacy": that is, a clear quantum speedup for *some* task, motivated by the goal of overturning the Extended Church-Turing Thesis (which says that all physical systems can be efficiently simulated by classical computers) as confidently as possible. Based on joint work with Lijie Chen, https://arxiv.org/abs/1612.05903

Time and fundamentals of quantum mechanics

Date:
27
Sunday
January
2019
-
01
Friday
February
2019
Conference
Time: 08:00
Location: David Lopatie Conference Centre

All Events

Chemical and Biological Physics dept Seminar

Date:
18
Thursday
January
2018
Lecture / Seminar
Time: 14:00
Title: Quantum disordered dynamics in the arrested relaxation of a molecular ultracold plasma
Location: Perlman Chemical Sciences Building
Lecturer: Prof. Edward Grant
Organizer: Department of Chemical and Biological Physics
Abstract: Spontaneous avalanche to plasma splits the core of an ellipsoidal Rydberg gas of ...Spontaneous avalanche to plasma splits the core of an ellipsoidal Rydberg gas of nitric oxide. Ambipolar expansion first quenches the electron temperature of this core plasma. Then, long-range, resonant charge transfer from ballistic ions to frozen Rydberg molecules in the wings of the ellipsoid quenches the centre-of-mass ion/Rydberg molecule velocity distribution. This sequence of steps gives rise to a remarkable mechanics of self-assembly, in which the kinetic energy of initially formed hot electrons and ions drives an observed separation of plasma volumes. These dynamics adiabatically sequester energy in a reservoir of mass transport, starting a process that anneals separating volumes to form an apparent glass of strongly coupled ions and electrons. Short-time electron spectroscopy provides experimental evidence for complete ionization. The long lifetime of this system, particularly its stability with respect to recombination and neutral dissociation, suggests that this transformation affords a robust state of arrested relaxation, far from thermal equilibrium. We argue that this state of the quenched ultracold plasma offers an experimental platform for studying quantum many-body physics of disordered systems in the long-time and finite energy-density limits. The qualitative features of the arrested state fail to conform with classical models. Here, we develop a microscopic quantum description for the arrested phase based on an effective many-body spin Hamiltonian that includes both dipole-dipole and van der Waals interactions. This effective model offers a way to envision the quantum disordered non-equilibrium physics of this system.

Special Colloquium in honor of Prof. Shimon Levit’s 70th birthday

Date:
28
Thursday
December
2017
Colloquium
Time: 11:15-12:30
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Mario Livio
Organizer: Faculty of Physics
Details: 11:00 Coffee, Tea and more
Abstract: HUMAN CURIOSITY The ability to ask “why?” makes us uniquely human. Curiosit ...HUMAN CURIOSITY The ability to ask “why?” makes us uniquely human. Curiosity drives basic scientific research, is the engine behind creativity in all disciplines from the arts to technology, is a necessary ingredient in education, and a facilitating tool in every form of storytelling (literature, film, TV, or even a simple conversation) that delights rather than bores. In a fascinating and entertaining lecture, astrophysicist and bestselling author Mario Livio surveys and interprets cutting-edge research in psychology and neuroscience that aims at exploring and understanding the origin and mechanisms of human curiosity. As part of his research into the subject, Livio examined in detail the personalities of two individuals who arguably represent the most curious minds to have ever existed: Leonardo da Vinci and Richard Feynman. He also interviewed 9 exceptionally curious people living today, among them Fabiola Gianotti, the Director General of CERN (who is also an accomplished pianist), paleontologist Jack Horner, and the virtuoso lead guitarist of the rock band Queen, Brian May (who also holds a PhD in astrophysics), and Livio presents fascinating conclusions from these conversations.

Quantization of heat flow in the fractional quantum Hall regime

Date:
21
Thursday
December
2017
Colloquium
Time: 11:15-12:30
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: TBA
Organizer: Faculty of Physics
Details: 11:00 Coffee, Tea and more
Abstract: Quantum mechanics sets an upper bound on the amount of charge flow as well as on ...Quantum mechanics sets an upper bound on the amount of charge flow as well as on the amount of heat flow in ballistic one-dimensional channels. The two relevant upper bounds, which combine only fundamental constants, are the quantum of the electrical conductance, Ge=e2/h, and the quantum of the thermal conductance, Gth=0T=(π2kB2/3h)T. Remarkably, the latter does not depend on the particles charge, particles exchange statistics, and is expected also to be insensitive to the interaction strength among the particles. However, unlike the relative ease in observing the quantization of the electrical conductance, measuring accurately the thermal conductance is more challenging. The universality of the Gth quantization in 1D ballistic channels was demonstrated for weakly interacting particles: phonons [1], photons [2], and in an electronic Fermi-liquid [3]. I will describe our recent experiments with heat flow in a strongly interacting system of 2D electrons in the fractional quantum Hall regime. In the lowest Landau level we studied particle-like states (v

AMPLITUDES AND HIDDEN SYMMETRIES IN N=2 CHERN-SIMONS MATTER THEORY

Date:
19
Tuesday
December
2017
Lecture / Seminar
Time: 12:00
Lecturer: KARTHIK INBASEKAR
Organizer: Department of Particle Physics and Astrophysics
Abstract: Abstract: Chern-Simons theories coupled to matter have a wide variety of applica ...Abstract: Chern-Simons theories coupled to matter have a wide variety of applications ranging from anyonic physics to quantum gravity via the AdS/CFT correspondence. These theories enjoy a strong-weak duality that has been tested to a very good accuracy via large N computations. Scattering amplitudes are some of the most basic observables in QFT's. S matrices computed to all orders in the 't Hooft coupling serve as important testing grounds for the strong-weak duality. Although beginning with 4 point amplitudes this is doable, the complexity of the problem increases with the number of external legs. As a first step towards computing all loop arbitrary n point amplitudes, we address the problem of computing arbitrary n point tree level amplitudes. We show that BCFW recursion relations can be used to compute all tree level scattering amplitudes in terms of $2 ightarrow2$ scattering amplitude in $U(N)$ ${mathcal N}=2$ Chern-Simons (CS) theory coupled to matter in fundamental representation. As a byproduct, we also obtain a recursion relation for the CS theory coupled to regular fermions, even though in this case standard BCFW deformations do not have a good asymptotic behavior. We then proceed to take the first steps towards all loop computations of arbitrary n point amplitudes. As a first step we explain the result of arXiv:1505.06571, where it was shown that the $2 ightarrow 2$ scattering is tree level exact to all orders except in the anyonic channel, where it gets renormalized by a simple function of 't Hooft coupling. We show that tree level $2 o 2$ scattering amplitudes in 3d ${cal N}=2$ Chern-Simons theory coupled to a fundamental chiral multiplet are dual superconformal invariant. We further show that the large $N$ all loop exact amplitude also has dual superconformal symmetry, which implies dual superconformal symmetry is all loop exact which is in contrast to other known highly supersymmetric examples such as ${cal N}=4$ SYM and ABJM where the dual superconformal symmetry is in general anomalous. The presence of superconformal and dual superconformal symmetry indicate the existence of a Yangian symmetry, further providing indications that the N=2 theory may be integrable.

Turbulence in a Localized Puff in a Pipe

Date:
18
Monday
December
2017
Lecture / Seminar
Time: 14:15
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Prof. Alex Yakhot
Organizer: Department of Physics of Complex Systems
Abstract: We have performed direct numerical simulations of transient turbulence in pipe f ...We have performed direct numerical simulations of transient turbulence in pipe flow for Re=2,250 which is established as a threshold of an equilibrium puff. We investigate the structure of an individual puff by considering three-dimensional snapshots across a long time-period. To assimilate the velocity data, we apply a conditional sampling based on the location of the maximum energy of the transverse (turbulent) motion. Specifically, at each time instance, we follow a turbulent puff by a three-dimensional moving-window centered at that location. We collected a snapshot-ensemble of the velocity fields acquired over 10,000 time instances (snapshots) inside the moving-window. The considered fow is intermittent and transitional. The velocity field inside the puff shows the dynamics of a developing turbulence. The localized puff is about of 12-15 pipe diameters long with almost laminar trailing and leading edges. In the puff core, despite the low Reynolds number, along the moving-window, it takes the downstream short distance of several pipe diameters to form the state of developed turbulence, when the turbulence statistics becomes similar to fully-developed turbulent pipe flow; the velocity profile becomes flat in the pipe core and logarithmic near the wall. It is shown that this “fully-developed turbulent slot” is very narrow, about two pipe diameters; it is localized and moves with a puff.

“A direct calculation of the lifetime of false vacua”

Date:
13
Wednesday
December
2017
Lecture / Seminar
Time: 13:00
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Dr.Ryosuke Sato
Organizer: Department of Particle Physics and Astrophysics
Abstract: Abstract: The lifetime of false vacua can be calculated by Coleman's semiclassic ...Abstract: The lifetime of false vacua can be calculated by Coleman's semiclassical method. This method implicitly uses a deformation of the potential. I will discuss an alternative approach to the calculation of the lifetime of the false vacua. References: Direct Approach to Quantum Tunneling Anders Andreassen, David Farhi, William Frost, Matthew D. Schwartz Published in Phys.Rev.Lett. 117 (2016) no.23, 231601 e-Print: arXiv:1602.01102 [hep-th] Precision decay rate calculations in quantum field theory Anders Andreassen, David Farhi, William Frost, Matthew D. Schwartz Published in Phys.Rev. D95 (2017) no.8, 085011 e-Print: arXiv:1604.06090 [hep-th]

Effective Force-laws for thermal amorphous solids

Date:
11
Monday
December
2017
Lecture / Seminar
Time: 14:15
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Yoav Pollack
Organizer: Department of Physics of Complex Systems

Wonders of viscous electronics

Date:
07
Thursday
December
2017
Colloquium
Time: 11:15-12:30
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Prof. Grisha Falkovich
Organizer: Faculty of Physics
Details: 11:00 Coffee, Tea and more
Abstract: Quantum-critical strongly correlated systems feature universal collision-dominat ...Quantum-critical strongly correlated systems feature universal collision-dominated collective transport. Viscous electronics is an emerging field dealing with systems in which strongly interacting electrons flow like a fluid. Such flows have some remarkable properties never seen before. I shall describe recent theoretical and experimental works devoted, in particular, to a striking macroscopic DC transport behavior: viscous friction can drive electric current against an applied field, resulting in a negative resistance, recently measured experimentally in graphene. I shall also describe conductance exceeding the fundamental quantum-ballistic limit, field-theoretical anomalies and other wonders of viscous electronics. Strongly interacting electron-hole plasma in high-mobility graphene affords a unique link between quantum-critical electron transport and the wealth of fluid mechanics phenomena.

Scaling up single-atom spin qubits in silicon

Date:
30
Thursday
November
2017
Colloquium
Time: 11:15-12:30
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Andrea Morello
Organizer: Faculty of Physics
Details: 11:00 Coffee, Tea and more
Abstract: The modern information era is built on silicon nanoelectronic devices. The futur ...The modern information era is built on silicon nanoelectronic devices. The future quantum information era might be built on silicon too, if we succeed in controlling the interactions between individual spins hosted in silicon nanostructures. Spins in silicon constitute excellent solid-state qubits, because of the weak spin-orbit coupling and the possibility to remove nuclear spins from the environment through 28Si isotopic enrichment. Substitutional 31P atoms in silicon behave approximately like hydrogen in vacuum, providing two spin 1/2 qubits -- the donor-bound electron and the 31P nucleus -- that can be coherently controlled [1,2], read out in single-shot [2,3], and are naturally coupled through the hyperfine interaction. In isotopically-enriched 28Si, these single-atom qubits have demonstrated outstanding coherence times, up to 35 seconds for the nuclear spin [4], and 1-qubit gate fidelities well above 99.9% for both the electron and the nucleus [5]. The hyperfine coupling provides a built-in interaction to entangle the two qubits within one atom. The combined initialization, control and readout fidelities result in a violation of Bell’s inequality with S = 2.70, a record value for solid-state qubits [6]. Despite being identical atomic systems, 31P atoms can be addressed individually by locally modifying the hyperfine interaction through electrostatic gating [7]. Multi-qubit logic gates can be mediated either by the exchange interaction [8] or by electric dipole coupling [9]. Scaling up beyond a single atom presents formidable challenges, but provides a pathway to building quantum processors that are compatible with standard semiconductor fabrication, and retain a nanometric footprint, important for truly large-scale quantum computers. [1] J.J. Pla et al., Nature 489, 541 (2012) [2] J.J. Pla et al., Nature 496, 334 (2013) [3] A. Morello et al., Nature 467, 687 (2010) [4] J.T. Muhonen et al., Nature Nanotech. 9, 986 (2014) [5] J.T. Muhonen et al., J. Phys.: Condens. Matt. 27, 154205 (2015) [6] J.P. Dehollain et al., Nature Nanotech. 11, 242 (2016) [7] A. Laucht et al., Science Advances 1, e1500022 (2015) [8] R. Kalra et al., Phys. Rev. X 4, 021044 (2014) [9] G. Tosi et al., Nature Communications 8:450 (2017)

Terrestrial glints seen from deep space: cloud ice crystals detected from the 1st Lagrangian point

Date:
26
Sunday
November
2017
Lecture / Seminar
Time: 11:00
Location: Sussman Family Building for Environmental Sciences
Lecturer: Alex Kostinski
Organizer: Department of Earth and Planetary Sciences
Abstract: The deep space climate observatory (DSCOVR) spacecraft resides at the 1st Lagran ...The deep space climate observatory (DSCOVR) spacecraft resides at the 1st Lagrangian point about one million miles from Earth, where roughly the solar pull balances the terrestrial one. A polychromatic imaging camera onboard delivers nearly hourly observations of the entire sun-lit face of the Earth. Many images contain surprisingly bright flashes of light over both ocean and land. We construct a yearlong time series of flash latitudes, scattering angles and oxygen absorption to demonstrate that the flashes over land are specular reflections off tiny cloud ice platelets. Such deep space detection of tropospheric ice can be used to constrain the likelihood of oriented crystals and their contribution to Earth albedo. These glints may help detecting starlight glints off faint companions in our search for habitable exoplanets.

The past of a quantum particle

Date:
23
Thursday
November
2017
Colloquium
Time: 11:15-12:30
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Lev Vaidman
Organizer: Faculty of Physics
Details: 11:00 Coffee, Tea and more
Abstract: Textbooks of quantum mechanics lack the concept of the past of quantum systems. ...Textbooks of quantum mechanics lack the concept of the past of quantum systems. Few years ago I proposed to define the past of a quantum particle according the trace it leaves. While in many cases this definition provides a reasonable description, for a nested Mach-Zehnder interferometer it leads to a picture seemingly contradicting common sense: the particle leaves a trace in a place through which it could not pass. I will discuss recent theoretical and experimental studies of this controversial issue.

Joint Chemical and Biological Physics and Organic Chemistry Seminar

Date:
21
Tuesday
November
2017
Lecture / Seminar
Time: 14:00
Title: Molecular water oxidation catalysts anchored on solid surfaces
Location: Gerhard M.J. Schmidt Lecture Hall
Lecturer: Prof. Antoni Llobet
Organizer: Department of Chemical and Biological Physics
Abstract: The replacement of fossil fuels by a clean and renewable energy source is one of ...The replacement of fossil fuels by a clean and renewable energy source is one of the most urgent and challenging issues our society is facing today, which is why intense research is devoted to this topic recently. Nature has been using sunlight as the primary energy input to oxidize water and generate carbohydrates (a solar fuel) for over a billion years. Inspired, but not constrained, by nature, artificial systems [1] can be designed to capture light and oxidize water and reduce protons or other organic compounds to generate useful chemical fuels. In this context this contribution will present a variety of molecular water oxidation catalysts based on transition metal complexes, together with their activity in homogeneous phase and anchored on solid surfaces to generate electro- and photo-anodes. A detailed analysis of their performance will be discussed.

Prof. Oded Aharonson - Space research, Israeli missions and the search for life in the universe

Date:
21
Tuesday
November
2017
Lecture / Seminar
Time: 12:00
Title: Space research, Israeli missions and the search for life in the universe
Location: Dolfi and Lola Ebner Auditorium
Lecturer: Prof. Oded Aharonson
Organizer: Department of Media Relations
Details: The lecture is in Hebrew

From strong passivity to extended second law of thermodynamics and new thermodynamic predictions on quantum microscopic systems

Date:
20
Monday
November
2017
Lecture / Seminar
Time: 14:15
Lecturer: Ram Uzdin, Technion
Organizer: Department of Physics of Complex Systems
Abstract: To thermodynamically address quantum nanoscopic scenarios that involve very smal ...To thermodynamically address quantum nanoscopic scenarios that involve very small heat sources and strong system-bath correlation, we suggest a new framework that is based on the principle of passivity. Passivity allows to get many thermodynamic inequalities that constrain observables that were so far outside the scope of thermodynamics. As an example we derive lower and upper bounds on the system-bath energy covariance in the Jaynes-Cummings model (spin-oscillator interaction). Using a stronger version of the passivity principle, we extend the second law to handle initial system-bath correlation (which is common in microscopic strong system-bath coupling scenarios). In addition, it is shown that passivity-based inequalities can detect "sub-Maxwellian” demons that apply a feedback that is too subtle to be detected using the standard second law. Finally an intrinsically quantum feature of strong passivity is exploited to assign a thermodynamic cost for quantum coherence generation.

Low Dimensional Colloidal Nano-Perovskites: Not Your Usual Quantum Dots

Date:
19
Sunday
November
2017
Lecture / Seminar
Time: 14:00-15:00
Location: Perlman Chemical Sciences Building
Lecturer: Dr. Yehonadav Bekenstein
Organizer: Department of Materials and Interfaces
Abstract: Thermodynamic considerations suggest correlation between efficient photo conver ... Thermodynamic considerations suggest correlation between efficient photo conversion and bright luminescence, in practice we do not usually see that. However, lead-halide perovskites do show excellent efficiencies in both photovoltaic and light-emitting applications. We study perovskite nanocrystals as a model system to further understand the origin of their enigmatic properties. Low-dimensional colloidal nano-crystals of cesium lead halide demonstrate exceptionally bright emission without shelling and unusual room temperature transformation not common to other semiconductors nanocrystals. These properties suggest a near equilibrium nanocrystal system. In a series of studies we follow the formation and transformations of these nanocrystals. We can now grow quantum confined cesium lead halide nanocrystals with cube, plate and wire shapes and with atomic precision. We demonstrate how quantum confinement and dimensionality dictate the exciton behavior and photophysical properties of these crystals. In the case of two dimensional nanoplates we observe strong quantum confinement of the excitons.(1) In the case of nanowires we show that broken symmetry manifests in significant polarized emission. These nanowires can be further utilized through 3D printing and alignment process to fabricate highly polarized functional metamaterials. In addition to the synthetic shape control, further control of the optical properties is achieved by changing the anion composition. The “softness” of the perovskite crystal allows post synthetic room temperature transformations that tune the material band-gap values throughout the visible spectrum.(2-3) The resulting high quantum yield, combined with the synthetic versatility and facile transformations, position colloidal perovskites as a unique model system for the study of charge dynamics and thermodynamic transformations at the nanoscale, contributing to the understanding of next generation materials for energy. Future developments in perovskites, leading to more stable and lead free materials will also be discussed

Small-Scale, Highly Precise Tests of the Standard Model and Its Symmetries

Date:
16
Thursday
November
2017
Colloquium
Time: 11:15-12:15
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Prof. Gerald Gabrielse
Organizer: Faculty of Physics
Details: 11:00 Coffee, Tea and more
Abstract: The Standard Model of particle physics is the great success and the great frustr ...The Standard Model of particle physics is the great success and the great frustration of modern physics. It is very surprising that the Standard Model can successfully predict what is measured to up to a part in 10^{12}, and yet be completely unable to explain either why a universe could survive the big bang or why it should be made of matter rather than antimatter. Low energy experiments play a crucial role in testing the Standard Model. The most precise prediction of the Standard Model, for example, was tested with one suspended electron used to make make the most accurate measurement of a property of an elementary particle. The symmetries of the Standard Model can be directly tested by comparing particles and antiparticles. Searches for physics beyond the Standard Model at energy scales at and above LHC energies are carried out by searching for an electric dipole moment of an electron in a polar molecule.

Theory and modeling of correlated ionic and electronic motions in hybrid organic-inorganic perovskites

Date:
16
Thursday
November
2017
Lecture / Seminar
Time: 11:00-12:00
Location: Perlman Chemical Sciences Building
Lecturer: Prof. Andrew Rappe
Organizer: Department of Materials and Interfaces
Abstract: The perovskite crystal structure hosts a wealth of intriguing properties, and th ...The perovskite crystal structure hosts a wealth of intriguing properties, and the renaissance of interest in halide (and hybrid organic-inorganic) perovskites (HOIPs) has further broadened the palette of exciting physical phenomena. Breakthroughs in HOIP synthesis, characterization, and solar cell design have led to remarkable increases in reported photovoltaic efficiency. However, the observed long carrier lifetime and PV performance have eluded comprehensive physical justification. The hybrid perovskites serve as an enigmatic crossroads of physics. Concepts from crystalline band theory, molecular physics, liquids, and phase transitions have been applied with some success, but the observations of HOIPs make it clear that none of these conceptual frameworks completely fits. In this talk, recent theoretical progress in understanding HOIPs will be reviewed and integrated with experimental findings. The large amplitude motions of HOIPs will be highlighted, including ionic diffusion, anharmonic phonons, and dynamic incipient order on various length and time scales. The intricate relationships between correlated structural fluctuations, polar order, and excited charge carrier dynamics will also be discussed.

Chemical and Biological Physics Dept Guest Seminar

Date:
15
Wednesday
November
2017
Lecture / Seminar
Time: 15:00
Title: ħ’s sign-reversal for spin-0 particle↔antiparticle transformation: anti-gravity and elimination of CPT-invariance
Location: Perlman Chemical Sciences Building
Lecturer: Prof Alexander E. Kaplan
Organizer: Department of Chemical and Biological Physics
Abstract: While revisiting Klein-Gordon relativistic quantum equation for spin-0 particles ...While revisiting Klein-Gordon relativistic quantum equation for spin-0 particles, we predicted that ħ reverses its sign for negative energies. We formulated a universal symmetry rule, whereby all the parameters that couple particles to external fields reverse their sign along with ħ at a particle↔antiparticle transformation. This in particular implies anti-gravitation between matter and antimatter. Our results suggest that the ħ-conjugation principle and related invariance may replace CPT-invariance in general relativistic quantum mechanics.

Chemical and Biological Physics Dept Guest Seminar

Date:
15
Wednesday
November
2017
Lecture / Seminar
Time: 10:00
Title: Feynman path integral approach to tunnelling time
Location: Gerhard M.J. Schmidt Lecture Hall
Lecturer: Dr Alexandra Landsman
Organizer: Department of Chemical and Biological Physics
Abstract: The tunnelling time problem is almost as old as quantum mechanics itself and is ...The tunnelling time problem is almost as old as quantum mechanics itself and is a highly debated subject. Time is not a quantum observable, and therefore many conflicting theories have been developed over the decades. Here we present the Feynman path integral (FPI) approach to tunnelling time, and show how it can be used to calculate tunnelling time probability amplitudes. The FPI approach also sheds new light on four best-known definitions of tunnelling times (Buttiker- Landauer, Pollak-Miller, Eisenbud-Wigner, and Larmor), which although derived using very different physical models, can also be represented as different averages using FPI tunnelling time probability amplitudes. Relation between the FPI approach, other tunnelling time definitions and the theory of weak measurement is also reviewed.

CARMENES: Searching for habitable planets around red stars

Date:
12
Sunday
November
2017
Lecture / Seminar
Time: 11:00
Location: Sussman Family Building for Environmental Sciences
Lecturer: Stefan Dreizler
Organizer: Department of Earth and Planetary Sciences

Search for new physics at the intensity frontier

Date:
09
Thursday
November
2017
Colloquium
Time: 11:15-12:15
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: TBA
Organizer: Faculty of Physics
Details: 11:00 Coffee, Tea and more
Abstract: With the discovery at the LHC of the Higgs boson, the main missing block of the ...With the discovery at the LHC of the Higgs boson, the main missing block of the Standard Model is now in place. An additional LHC result of great importance is that a large new territory has been explored and no unambiguous signal of New Physics has been found. However some new particles or interactions are required to explain a number of observed phenomena in particle physics, astrophysics, and cosmology as the neutrino masses, the baryon asymmetry of the universe, the Dark Matter and the cosmological inflation. So far the experimental efforts have been concentrated on the discovery of new particles with masses at or above the EW scale with sizable couplings with SM particles. Another viable possibility, largely unexplored, is that these new particles are below the EW scale and have not been detected because they interact very feebly with the SM particles. I will review the current status of the search for these new particles with masses in the MeV-GeV region at beam dump experiments currently running or proposed at CERN.

Foundations of Computer Science Seminar

Date:
06
Monday
November
2017
Lecture / Seminar
Time: 14:30-16:00
Title: New Results on Learning and Reconstruction of Quantum States
Location: Jacob Ziskind Building
Lecturer: Scott Aaronson
Organizer: Department of Mathematics
Abstract: ...

Foundations of Computer Science Seminar

Date:
06
Monday
November
2017
Lecture / Seminar
Time: 14:30-16:00
Title: New Results on Learning and Reconstruction of Quantum States
Location: Jacob Ziskind Building
Lecturer: Scott Aaronson
Organizer: Department of Computer Science and Applied Mathematics
Abstract: ...

Foundations of Computer Science Seminar

Date:
06
Monday
November
2017
Lecture / Seminar
Time: 14:30-16:00
Title: New Results on Learning and Reconstruction of Quantum States
Location: Jacob Ziskind Building
Lecturer: Scott Aaronson
Organizer: Faculty of Mathematics and Computer Science
Abstract: ...

Memory of species’ coexistence in ecological communities

Date:
06
Monday
November
2017
Lecture / Seminar
Time: 14:15
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Guy Bunin
Organizer: Department of Physics of Complex Systems
Abstract: Communities of coexisting species are shaped by the interactions between them, a ...Communities of coexisting species are shaped by the interactions between them, and by the motion of organisms. How does the network of interactions organize in response to these processes? Using a systematic analytical framework we calculate properties of the matrix of pair-interactions, reduced to the subset of species that are able to coexist. This reduced matrix acquires new statistical structure such as correlations between its elements. Yet to fully explain species coexistence one must go beyond simple correlations, to find a structure that is closely related to memory patterns in models of neural networks.

The optics of life

Date:
02
Thursday
November
2017
Colloquium
Time: 11:15-12:15
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Prof. Dan Oron
Organizer: Faculty of Physics
Details: 11:00 Coffee, Tea and more
Abstract: Light is the source of life on Earth, and is used in numerous ways in the plant ...Light is the source of life on Earth, and is used in numerous ways in the plant and animal kingdoms for a variety of applications, including photosynthesis, vision, camouflage, communication, thermal management and more. As such, evolution has led to the creation of intricate optical systems with highly controlled and regulated properties. The talk will present an overview of some of these unique optical systems, focusing on the ubiquitous guanine-based optical reflectors and on mineral deposits in leaves of higher plants. In particular, correlated optical and structural characterization will be shown to reveal new information about the function of some of the more poorly understood biological light manipulation systems and to reveal clues about their evolution.

Interfacing Single Electron Spins with a Quantum Bus

Date:
26
Thursday
October
2017
Colloquium
Time: 11:15-12:15
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Prof. Jason Petta
Organizer: Faculty of Physics
Details: 11:00 Coffee, Tea and more
Abstract: Tremendous progress has been achieved in the coherent control of single quantum ...Tremendous progress has been achieved in the coherent control of single quantum states (single charges, phonons, photons, and spins). At the frontier of quantum information science are efforts to hybridize different quantum degrees of freedom. For example, by coupling a single photon to a single electron fundamental light-matter interactions may be examined at the single particle level to reveal exotic quantum effects, such as single atom lasing. Coherent coupling of spin and light, which has been the subject of many theoretical proposals over the past 20 years, could enable a quantum internet where highly coherent electron spins are used for quantum computing and single photons enable long-range spin-spin interactions. In this colloquium I will describe experiments where we couple a single spin in silicon to a single microwave frequency photon. The coupling mechanism is based on spin-charge hybridization in the presence of a large magnetic field gradient. Spin-photon coupling rates gs/2 > 10 MHz are achieved and vacuum Rabi splitting is observed in the cavity transmission, indicating single spin-photon strong coupling. These results open a direct path toward entangling single spins at a distance using microwave frequency photons.

HESTPV Solar ERAnet October 2017 meeting

Date:
24
Tuesday
October
2017
Conference
Time: 08:00
Location: Michael and Anna Wix Auditorium

AMO Special Seminar

Date:
19
Tuesday
September
2017
Lecture / Seminar
Time: 13:15-14:30
Title: PhD Defense
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Yehonatan Gilead , Weizmann Institute of Science
Organizer: Department of Physics of Complex Systems

AMO Special Seminar

Date:
05
Tuesday
September
2017
Lecture / Seminar
Time: 13:15-14:30
Title: Nonlinear quantum optics in nanophotonic waveguides
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Dr. Hashem Zoubi, Leibniz Universität Hannover, Germany
Organizer: Department of Physics of Complex Systems

AMO Special Seminar

Date:
29
Tuesday
August
2017
Lecture / Seminar
Time: 13:15-14:30
Title: Quantum Simulation of Lattice Gauge Theories: from Analog to Digital
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Dr. Erez Zohar, Max-Planck-Institut für Quantenoptik, Germany
Organizer: Department of Physics of Complex Systems
Abstract: Gauge theories are not only important and fundamental in modern physics, they al ...Gauge theories are not only important and fundamental in modern physics, they also present some hard, challenging puzzled waiting to be solved. In the recent years, quantum information, optics and atomic physics have proposed two new approaches for studying such theories: tensor networks studies and quantum simulation. In my talk I will discuss the latter, present some analog quantum simulation schemes using ultracold atoms, and focus on a recent, digital formulation of lattice gauge theories that decomposes four-body interactions from two-body ones, allowing for digital quantum simulation schemes with atomic systems.

G-INCPM Special Seminar - Prof. Abraham Shanzer, The Dept. of Organic Chemistry, Weizmann Institute - "Biomimetic Chemistry: Mimicking Biological Diversity & Addressing Technological Challenges"

Date:
26
Wednesday
July
2017
Lecture / Seminar
Time: 11:00-12:30
Location: Nancy and Stephen Grand Israel National Center for Personalized Medicine
Lecturer: Prof. Abraham Shanzer
Organizer: Department of Biomolecular Sciences
Abstract: ‘Biomimetic Chemistry’ presents a conceptual approach to the art of model bu ...‘Biomimetic Chemistry’ presents a conceptual approach to the art of model building attempting to imitate the activity of a biological system by emphasis on the function of a substrate rather than on its detailed molecular structure. In the talk today I will center on the approach, governing the fundamental phenomenon of molecular recognition. The end goal is to formulate a set of rules essential to the design of molecules matching a specific biological system. Microbial iron-carriers, Siderophores, provide a useful platform for studying these principles. Several series of ferrichrome biomimetic analogs varying in length and polarity of the chains separating between the tripodal scaffold and the pendent FeIII chelating hydroxamic acid groups were prepared and studied. Microbial growth promotion was conducted on bacteria (E. coli, and P. putida) and fungi (U. maydis). These studies show a wide range of siderophore activity: from a rare case of species-specific growth promotor in P. putida to an analog with broad-spectrum activity matching ferrichrome in cross-phylum activity and uptake pathway. A fluorescent conjugate, to the broad-rang analog, provide clear images of the iron-free siderophore final destination in bacteria (periplasmic space) vs fungi (cytosol) mapping distinctly new therapeutic targets. Quantum Dots (QD) decorated with the most potent ferrichrome (FC) analog provided a tool for immobilization of FC-recognizing bacteria. Bacterial clusters formed around QDs, provide a platform for their selection and concentration. The fascinating field of lanthanide-clusters will be introduces and their unique properties describe, possible future opportunities and application will be discussed.

AMO Special Seminar

Date:
23
Sunday
July
2017
Lecture / Seminar
Time: 11:00
Title: Dipolar quantum droplets and stripes in dysprosium Bose-Einstein condensates
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Dr. Igor Ferrier-Barbut
Organizer: Department of Physics of Complex Systems
Abstract: I will present experimental results on magnetic quantum fluids. These consist of ...I will present experimental results on magnetic quantum fluids. These consist of a dilute Bose-Einstein condensate of dysprosium atoms, the most magnetic stable element. They allow to study the many-body consequences of the anisotropic and long-range dipole-dipole interaction, benefitting from the control tools of ultracold atomic physics. First, we have observed in this system an unanticipated phase-transition between a gas and a liquid, characterized by the formation of self-bound droplets [1-3]. It forms in a parameter region where the existing theory, based on the mean-field approximation, predicted a mechanical collapse of the gas. We showed that the repulsive beyond meanfield corrections prevent the collapse and are responsible for the stabilization of the liquid [2]. These corrections arise from quantum fluctuations (zero-point motion) of the collective modes (Bogolyubov sound modes) in the quantum fluid. In recent work we show that in constrained geometries, the ground-state is selforganized (left image). Studying these geometries experimentally, we indeed observe stable self-organized ‘stripe’ phases (right image), likely in metastable excited states. I will discuss the prospects for a strange kind of supersolidity in this system. In other experiments we study the effect of a rotating magnetic field on a quantum droplet, as a tool for the study of the different low-lying collective modes of the system. [1] Observing the Rosensweig instability of a quantum ferrofluid, H. Kadau, M. Schmitt, M. Wenzel, C. Wink, T. Maier, I. Ferrier-Barbut, and T. Pfau, Nature 530, 194 (2016). [2] Observation of quantum droplets in a strongly dipolar Bose gas, I. Ferrier-Barbut, H. Kadau, M. Schmitt, M. Wenzel, and T. Pfau, Phys. Rev. Lett. 116, 215301 (2016). [3] Self-bound droplets of a dilute magnetic quantum liquid, M. Schmitt, M. Wenzel, F. Böttcher, I. Ferrier-Barbut and T. Pfau, Nature 539, 259 (2016).

AMO Special Seminar

Date:
18
Tuesday
July
2017
Lecture / Seminar
Time: 13:15
Title: Towards high precision frequency comb spectroscopy in the extreme ultraviolet
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Dr. Gil Porat
Organizer: Department of Physics of Complex Systems
Abstract: High precision spectroscopy of few-electron atoms and ions is strongly motivated ...High precision spectroscopy of few-electron atoms and ions is strongly motivated by the need to test fundamental theory (e.g., quantum electrodynamics) in simple systems, amenable to precise calculation for comparison with experimental measurement. Additionally, transitions from the ground state are most susceptible to both QED and nuclear structure effects, making them appealing as tools for testing nuclear structure theory. The frequencies of transitions from the ground state in many such systems reside in the extreme ultraviolet range of the electromagnetic spectrum (XUV, wavelengths of 10-120 nm). However, spectroscopic resolution in the XUV is severely limited by the availability of appropriate sources of XUV radiation. In this talk I will discuss our experimental method of generating an XUV frequency comb laser, and our progress in scaling up the power of this laser in order to enable the highest spectroscopic precision in the XUV to date.

AMO Special Seminar

Date:
11
Tuesday
July
2017
Lecture / Seminar
Time: 13:15
Title: The temporal structure of ultra-fast rogue waves
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Dr. Moti Fridman
Organizer: Department of Physics of Complex Systems
Abstract: Extreme waves suddenly appearing from noisy background and disappearing immediat ...Extreme waves suddenly appearing from noisy background and disappearing immediately after. Ancient tales from sailors on such waves were told but considered as a pure myth. We investigate the dynamics of optical rogue waves in a record high resolution and focused on their power dependence and vectorial nature. We demonstrated three types of rogue waves and claim that all known mechanisms can not explain our findings, and therefore, a new mechanism must be considered.

AMO Journal Club

Date:
04
Tuesday
July
2017
Lecture / Seminar
Time: 13:15
Location: Edna and K.B. Weissman Building of Physical Sciences
Organizer: Department of Physics of Complex Systems
Abstract: Speakers: Dekel Raanan, Eilon Poem-Kalogerakis ...Speakers: Dekel Raanan, Eilon Poem-Kalogerakis

Magnetic Resonance Seminar

Date:
29
Thursday
June
2017
Lecture / Seminar
Time: 09:30
Title: Sub-milliherz magnetic spectroscopy with a nanoscale quantum sensor
Location: Gerhard M.J. Schmidt Lecture Hall
Lecturer: Alex Retzker
Organizer: Department of Chemical and Biological Physics
Abstract: Precise timekeeping is critical to metrology, forming the basis by which standar ...Precise timekeeping is critical to metrology, forming the basis by which standards of time, length and fundamental constants are determined. Stable clocks are particularly valuable in spectroscopy as they define the ultimate frequency precision that can be reached. In quantum metrology, where the phase of a qubit is used to detect external fields, the clock stability is defined by the qubit coherence time, and therefore determines the spectral linewidth and frequency precision. I will present a demonstration of a quantum sensing protocol for oscillating fields where the spectral precision goes beyond the sensor coherence time and is limited by the stability of a classical clock. Using this technique, we observe a precision in frequency estimation scaling as1/T^{3/2}for classical fields. The narrow linewidth magnetometer based on single quantum coherent spins in diamond is used to sense magnetic fields with an intrinsic frequency resolution of 607µHz, 8 orders of magnitude narrower than the qubit coherence time

AMO Journal Club

Date:
27
Tuesday
June
2017
Lecture / Seminar
Time: 13:15
Location: Edna and K.B. Weissman Building of Physical Sciences
Organizer: Department of Physics of Complex Systems

The Quantum Design of Photosynthesis

Date:
26
Monday
June
2017
Lecture / Seminar
Time: 11:00-12:00
Location: Perlman Chemical Sciences Building
Lecturer: Prof. Rienk van Grondelle
Organizer: Department of Materials and Interfaces
Details: In photosynthesis sunlight is absorbed by the photosynthetic pigments, chlorophyll and carotenoid and the resulting excited state is stored as chemical energy. This energy conversion under optimal conditions occurs with a remarkable efficiency that scientists hope to mimick in bio-inspired solar energy converting devices, based on abundant elements. Two ultrafast (femtoseconds-picoseconds, 10-15-10-12 sec) processes are at the basis of the success of photosynthesis: excitation energy transfer in a light-harvesting antenna followed by charge separation in the photosynthetic reaction center. In plants pigments involved in light-harvesting antenna and charge separation are bound to specialized proteins that are organized in a membrane, the thylakoid membrane. Plants make do with two reaction centers that operate in series, Photosystem 1 and Photosystem 2, the former is sufficiently reducing to reduce CO2, the latter has the capacity to extract the necessary electrons from water and produce molecular oxygen. Upon absorption of light collective excitations (excitons) are formed that are delocalized over a number of pigments that move extremely rapidly through the light-harvesting antenna to the reaction center in such a way that the quantum coherence is maintained even during the final charge separation. Two-dimensional (2D) electronic spectroscopy is an ultrafast laser technique that allows a visualization of how these coherences are involved in the primary processes of energy and charge transfer. Based on quantitative modeling we identify the exciton-vibrational coherences observed in 2D photon echo of the photosystem II reaction center (PSII-RC). We find that the vibrations resonant with the exciton splittings can modify the delocalization of the exciton states and produce additional states, thus promoting directed energy transfer and allowing a switch between the two charge separation pathways. We conclude that the coincidence of the frequencies of the most intense vibrations with the splittings within the manifold of exciton and charge-transfer states in the PSII-RC is not occurring by chance, but reflects a fundamental principle of how energy conversion in photosynthesis was optimized. For a recent review of this work see: Romero, E., Novoderezhkin, V.I. and van Grondelle, R., Quantum Design of Photosynthesis for Bio-inspired Solar Energy Conversion, Nature 543, 355-365 (2017) http://rdcu.be/p6Wg

Scanning New Horizons:Entanglement, Holography & Gravity

Date:
22
Thursday
June
2017
Colloquium
Time: 11:15-12:30
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Rob Myers
Organizer: Faculty of Physics
Details: 11:00 – coffee, tea, and more
Abstract: New advances and insights often emerge from the confluence of different ideas co ...New advances and insights often emerge from the confluence of different ideas coming from what appeared to be disconnected research areas. The theme of my talk will review an ongoing collision between the three topics listed in the title above which has been generating interesting new insights about the nature of quantum gravity, as well as other fields, eg, condensed matter physics and quantum field theory.

AMO Journal Club

Date:
20
Tuesday
June
2017
Lecture / Seminar
Time: 13:15
Location: Edna and K.B. Weissman Building of Physical Sciences
Organizer: Department of Physics of Complex Systems
Abstract: Speakers: Yehonathan Drori, Dimitry Yankelev ...Speakers: Yehonathan Drori, Dimitry Yankelev

Dr. Doron Kushnir - The astrophysics behind the discovery of gravitational waves

Date:
15
Thursday
June
2017
Lecture / Seminar
Time: 12:00
Title: The astrophysics behind the discovery of gravitational waves
Location: Dolfi and Lola Ebner Auditorium
Lecturer: Dr. Doron Kushnir
Organizer: Department of Media Relations
Details: The lecture is in Hebrew

Measurements of resonant transitions in trapped antihydrogen atoms

Date:
15
Thursday
June
2017
Colloquium
Time: 11:15-12:30
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Eli Sarid
Organizer: Faculty of Physics
Details: 11:00 – coffee, tea, and more
Abstract: Comparison of the properties of matter and antimatter is an important basic phys ...Comparison of the properties of matter and antimatter is an important basic physics problem. Measurements of energy transitions in trapped antihydrogen and their comparison to the transitions in hydrogen atoms can be used as a sensitive test of CPT symmetry. The ALPHA collaboration in CERN first demonstrated trapping of cold antihydrogen atoms in 2010 [1], demonstrating later long time capture of 15 minutes and more. As a first demonstration of introducing resonant transitions between levels of trapped antihydrogen atoms [2], ALPHA used microwave radiation (2012) to induce transitions between the hyperfine levels of the ground state of the antiatoms. Last year (2016) we performed the first ever measurement of the resonant transition 1S→2S in antihydrogen, using two-photon laser excitation with 243 nm light [3]. These initial measurements indicated that the antihydrogen 1S→2S transition energy is equal to its hydrogen counterpart at the level of about 2×10-10. With improved techniques that enable us now to trap on average 14 antiatoms per trial, ALPHA plans to perform increasingly precise spectroscopy CPT tests. A new system is also being constructed to enable measurements of the gravitational free fall of antihydrogen. [1] Trapped Antihydrogen, Nature 468,673 (2010). [2] Resonant quantum transitions in trapped antihydrogen atoms, Nature, 483, 439 (2012). [3] Observation of the 1S–2S transition in trapped antihydrogen, Nature, 541, 506 (2017).

AMO Special Seminar

Date:
14
Wednesday
June
2017
Lecture / Seminar
Time: 10:15
Title: Quantum cascade lasers and frequency combs: towards chip-based optical chemical sensors
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Jérôme Faist
Organizer: Department of Physics of Complex Systems
Abstract: The mid-infrared and terahertz spectral range is key to many applications for se ...The mid-infrared and terahertz spectral range is key to many applications for sensing and imaging, as many molecules have their fundamental vibration modes in that frequency region. Using traditional multipass cells and single frequency quantum cascade lasers, detection of light molecules with sup-ppb sensitivity and isotopic selectivity has been achieved. There is a strong interest in extending these results to multiple gases and to miniaturized, portable systems. Towards this goal, the recent demonstration of comb operation in quantum cascade lasers opens up new avenues for broadband spectroscopy. We recently demonstrated a comb device delivering 1 watt of optical power over a bandwidth of more than 100cm-1 at 8um wavelength. These devices were achieved by a engineering the waveguide dispersion using plasmonic resonances. We also discuss the prospects of performing self-referencing after achieving an octave-spanning gain in the Terahertz.

AMO Journal Club

Date:
13
Tuesday
June
2017
Lecture / Seminar
Time: 13:15-14:15
Location: Edna and K.B. Weissman Building of Physical Sciences
Organizer: Department of Physics of Complex Systems
Abstract: Speakers: Ronen Chriki, Gidi Alon ...Speakers: Ronen Chriki, Gidi Alon

AMO Special Seminar

Date:
11
Sunday
June
2017
Lecture / Seminar
Time: 13:15
Title: High order correlations and what we can learn about the solution for many body problems from experiment
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Prof. Jörg Schmiedmayer
Organizer: Department of Physics of Complex Systems
Abstract: The knowledge of all correlation functions of a system is equivalent to solving ...The knowledge of all correlation functions of a system is equivalent to solving the corresponding quantum many-body problem. If one can identify the relevant degrees of freedom, the knowledge of a finite set of correlation functions is in many cases sufficient to determine a sufficiently accurate solution of the corresponding field theory. Complete factorization is equivalent to identifying the relevant degrees of freedom where the Hamiltonian becomes diagonal. I will give examples how one can apply this powerful theoretical concept in experiment. Work performed in collaboration with E.Demler (Harvard), Th. Gasenzer und J. Berges (Heidelberg). Supported by the Wittgenstein Prize, the Austrian Science Foundation (FWF): SFB FoQuS: F40-P10 and the EU: ERC-AdG QuantumRelax [1] M. Gring et al., Science, 337, 1318 (2012); [2] T. Langen et al., Science 348 207-211 (2015). [3] T. Schweigler et al., Nature 545, 323 (2017), arXiv:1505.03126

Electrified dust storms on Earth and other planets

Date:
11
Sunday
June
2017
Lecture / Seminar
Time: 11:00
Location: Sussman Family Building for Environmental Sciences
Lecturer: Yoav Yair
Organizer: Department of Earth and Planetary Sciences

AMO Journal Club

Date:
06
Tuesday
June
2017
Lecture / Seminar
Time: 13:15-14:15
Location: Edna and K.B. Weissman Building of Physical Sciences
Organizer: Department of Physics of Complex Systems
Abstract: Speakers: Meirav Pinkas, Anat Daniel ...Speakers: Meirav Pinkas, Anat Daniel

AMO Special Seminar

Date:
05
Monday
June
2017
Lecture / Seminar
Time: 11:00
Title: Photon Processing in the Frequency Domain
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Prof. Alexander Gaeta
Organizer: Department of Physics of Complex Systems
Abstract: Nonlinear optical processes play a central role in many quantum information devi ...Nonlinear optical processes play a central role in many quantum information devices. I will describe our recent work in which we explore the use of quantum frequency conversion based on four-wave mixing to process photons with high quantum efficiency without adding noise. I will describe how we use this conversion process to create a single-photon Ramsey interferometer, temporally magnify photon wavepackets, and perform frequency multiplexing to create a quasi-deterministic photon source.

Unusual quasiparticle correlation in graphene

Date:
25
Thursday
May
2017
Colloquium
Time: 11:15-12:30
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Philip Kim
Organizer: Faculty of Physics
Details: 11:00 – coffee, tea, and more
Abstract: Interactions between particles in quantum many-body systems can lead to a collec ...Interactions between particles in quantum many-body systems can lead to a collective behavior. In a condensed matter system consisting of weakly interacting particles, a propagating particle interacting with its surroundings can be viewed as a ‘dressed’ quasiparticle with renormalized mass and other dynamic properties. The lack of screening enables strong Coulomb interactions between charged particles, leading to new collective dynamics. In this talk, I will discuss three examples concerning strongly interacting quasiparticles in graphene. In the first example, it will be shown that the thermally populated electrons and holes to realize Dirac fluid, where a huge violation of Wiedemann-Franz law is observed. The second example is realizing magnetoexcitons to correlated the quasiparticles in quantized Landau levels to form magnetoexcitons, which can condense into Bose-Einstein condensation. Finally, we will also discuss another way of correlated quasi-particles in graphene using superconducting proximity effect. Here, we employ the crossed Andreev reflection across thin type II superconducting electrodes to correlated spatially separated quasiparticles. Under strong magnetic fields, the quantum Hall edge states can carry these quasiparticles.

AMO Journal Club

Date:
23
Tuesday
May
2017
Lecture / Seminar
Time: 13:15-14:15
Location: Edna and K.B. Weissman Building of Physical Sciences
Organizer: Department of Physics of Complex Systems
Abstract: Speakers: Ruti Ben-Shlomi, Gal Winer ...Speakers: Ruti Ben-Shlomi, Gal Winer

AMO Special Seminar

Date:
18
Thursday
May
2017
Lecture / Seminar
Time: 11:15-12:00
Title: Quantum state monitoring and control via unsharp measurements
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Dr. Hermann Uys
Organizer: Department of Physics of Complex Systems
Abstract: Typical experiments on quantum systems rely on open-loop dynamics that is probed ...Typical experiments on quantum systems rely on open-loop dynamics that is probed with projective measurements. We explore the use of the broader class of POVM measurements allowed within quantum theory both for real-time monitoring of quantum states and quantum control. In particular, we discuss unsharp measurements as a tool to probe dynamic correlation functions during quantum quench dynamics in many particle spin systems. We derive an unsharp measurement protocol applicable to arbitrary spin, and find the surprising result that projective measurements allow exact extraction of correlation functions in the case of spin 1/2. Secondly, I present a protocol for quantum state monitoring using sequential unsharp measurement that allows real-time state estimation with high fidelity. By combining measurement with feedback based on an a priori (potentially incorrect) assumption regarding the pre-measurement state, we show that one can drive the quantum state into the assumed state. We call this control by a self-fulfilling prophecy.

You can hide but you have to run: new theory tools to unveil the mystery of dark matter

Date:
17
Wednesday
May
2017
Lecture / Seminar
Time: 10:45
Lecturer: Francesco D’Eramo
Organizer: Department of Particle Physics and Astrophysics
Details: 10:45 Coffee 12:15 Lunch
Abstract: The origin and composition of 85% of the matter in the universe is completely un ...The origin and composition of 85% of the matter in the universe is completely unknown. Among several viable options, Weakly Interacting Massive Particles (WIMPs) are motivated dark matter candidates that can be tested by different and complementary search strategies. Crucially, different searches probe WIMP couplings at different energy scales, and such a separation of scales has striking consequences in connecting different experimental probes. This motivates the development of theoretical tools to properly connect the different energy scales involved in constraining WIMP models. I will introduce these tools and I will illustrate with several examples how crucial the inclusion of these effects in WIMP searches is.

AMO Journal Club

Date:
16
Tuesday
May
2017
Lecture / Seminar
Time: 13:00-14:00
Location: Edna and K.B. Weissman Building of Physical Sciences
Organizer: Department of Physics of Complex Systems
Abstract: Speakers: Yuval Rosenberg, Barry Bruner ...Speakers: Yuval Rosenberg, Barry Bruner

Symposium in honor of Prof. Eytan Domany on the occasion of his 70th birthday

Date:
16
Tuesday
May
2017
-
17
Wednesday
May
2017
Lecture / Seminar
Time: 09:00 - 17:00
Location: Edna and K.B. Weissman Building of Physical Sciences
Organizer: Department of Physics of Complex Systems
Details: https://app.box.com/s/315cxers81n2h2imcccw6lfdhe1bc99q

"New insights about transcription dynamics at the single molecule level using ultra-high resolution optical tweezers and novel analysis algorithms"

Date:
09
Tuesday
May
2017
Lecture / Seminar
Time: 14:00-15:00
Location: Gerhard M.J. Schmidt Lecture Hall
Lecturer: Dr. Ronen Gabizon
Organizer: Department of Physics of Complex Systems
Abstract: Transcription elongation by RNA polymerase (RNAP) is a complex process involving ...Transcription elongation by RNA polymerase (RNAP) is a complex process involving binding of nucleotides, conformational changes, catalytic steps, and translocation on the DNA template. The processive elongation is interspersed with transcriptional pauses, which play critical roles in coordinating transcription with processes such as translation, splicing and DNA repair. While many mechanisms contributing to pausing have been characterized, it is not clear how transcriptional dynamics of RNA polymerase change at pause sites, and how those dynamics lead to the formation of various paused states. I will present high-resolution optical tweezers experiments in which we characterize the transcription of individual E. coli RNA polymerase molecules through repeating templates. Combining the assay with novel methods of data analysis, we were able to separately investigate the pausing dynamics at different sites for pauses as short as 100 msec, and test how these dynamics are affected by applied force, backtracking and RNA structure formation. Our experiments revealed that: 1. Multiple mechanisms act in synergy to promote pausing in a site-specific manner; 2. RNA structure interacts primarily with the pretranslocated state of RNAP and can both promote or prevent pausing; 3. Backtracked pause states are formed in a site-specific manner and can only be accessed from preexisting paused states. In the second part of the talk I will discuss the application of optical tweezers towards characterizing the stepping behavior of RNA polymerase during active elongation. Individual base-pair steps (~ 3.4 Å) have been observed before in optical tweezers assays but only anecdotally and for short segments of transcription traces. By combining an ultra-high resolution optical tweezers system with a Large-state-space Hidden Markov Model step finding algorithm, we are now able to obtain for the first time full, extended molecular trajectories of RNAP with single base-pair resolution.

Special Magnetic Resonance Seminar

Date:
09
Tuesday
May
2017
Lecture / Seminar
Time: 12:00
Title: NMR Experiments for One and Two Receivers
Location: Perlman Chemical Sciences Building
Lecturer: Eriks Kupce
Organizer: Department of Chemical and Biological Physics
Abstract: Can 13C-direct detection experiments be more sensitive than their 1H detected co ...Can 13C-direct detection experiments be more sensitive than their 1H detected counterparts? We show one such example focusing on the impact of t1-noise and the ways to reduce it or avoid it altogether. The applications include so far difficult measurements of 15N-13C couplings at the natural isotopic abundance [1]. NMR experiments involving multiple receivers provide a unique way of increasing the sensitivity and information content of data recorded in a given period of time [2-4]. We present a comprehensive series of such experiments designed for simultaneous detection of abundant nuclei, such as 1H, 19F and 31P, as well as samples enriched with magnetically active isotopes including 13C and 15N. The multiple receiver experiments are categorized into three main types – (a) parallel acquisition, (b) sequential acquisition and (c) interleaved experiments. The optimum implementation is shown to depend on the relaxation properties of the involved nuclei as well as the intrinsic sensitivity of the directly observed nuclei. Many of these experiments are amenable to further reduction of experiment time by combining them with other fast NMR techniques, such as Hadamard NMR, non-uniform sampling, spatial encoding or rapid pulsing methods. We believe that the multi-receiver technology will boost the development of new NMR experiments as well as NMR research in general, making the NMR instruments more efficient and making the NMR spectroscopy even more unique in the universe of analytical tools and experimental techniques.

AMO Special Seminar

Date:
09
Tuesday
May
2017
Lecture / Seminar
Time: 11:30-12:30
Title: Cold molecules - a new playground for quantum and chemical physics
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Prof. Jun Ye
Organizer: Department of Physics of Complex Systems
Abstract: Molecular interactions control everything from making new materials to generatio ...Molecular interactions control everything from making new materials to generation of energy. However, the complexity of molecular structure and interactions has challenged accurate study and precise control of dynamics. A new scientific frontier is emerging in recent years with the work of cooling molecules to low temperatures, aiming to achieve precise control of molecular interaction processes. This is motivated by new opportunities where fundamental insights of how molecule interact and evolve will allow us to design and control chemistry and quantum materials. The capability of tracking how molecules approach each other, form short-lived intermediates, and then reemerge with final products can help illuminate the most fundamental aspects of reaction processes. When a quantum gas of molecule is produced, we can arrange molecules in particular spatial configurations and precisely manipulate their interactions via external electromagnetic fields. The long-range dipolar interaction between trapped molecules presents an interconnected spin system where correlated many-body dynamics can be explored.

Example 1 for internal event node

Date:
08
Monday
May
2017
-
10
Wednesday
May
2017
Retreat
Time: 10:00 - 12:30
Location: David Lopatie Conference Centre ...
Organizer: Department of ...

Example 2 for internal event node

Date:
08
Monday
May
2017
-
10
Wednesday
May
2017
Retreat
Time: 10:00 - 12:30
Location: David Lopatie Conference Centre ...
Organizer: Department of ...

AMO Special Seminar

Date:
27
Thursday
April
2017
Lecture / Seminar
Time: 13:15-14:15
Title: Quantum technologies and quantum control
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Prof. Tommaso Calarco
Organizer: Department of Physics of Complex Systems
Details: The control of quantum states is essential both for fundamental investigations and for technological applications of quantum physics. In quantum few-body systems, decoherence arising from interaction with the environment hinders the realization of desired processes. In quantum many-body systems, complexity of their dynamics further makes state preparation via external manipulation highly non-trivial. An effective strategy to counter these effects is offered by quantum optimal control theory, exploiting quantum coherence to dynamically reach a desired goal with high accuracy even under limitations on resources such as time, bandwidth, and precision. In this talk I will: - introduce the quantum optimal control method we developed to this aim, the CRAB (Chopped Random Basis) algorithm, which is to date the only method that allows to perform optimal control of quantum many-body systems; - present experimental results obtained via its application to various physical systems, from quantum logical operations in solid-state quantum optics to quantum criticality in ultra-cold atoms, both in open-loop and in closed-loop feedback scenarios, with applications ranging from quantum interferometry with Bose-Einstein condensates on atom chips to magnetic field sensing in diamond NV centers and to the preparation of optical-lattice quantum registers for quantum simulation; - use these examples to illustrate the quantum speed limit, i.e. the maximum speed achievable for a given quantum transformation, and describe related effects of nonlinearity due to inter-particle interactions and more in general to dynamical complexity; - propose a way to characterise the latter in an information-theoretical fashion by the bandwidth of the optimized control pulses, as well as a conjecture about using this method for discrimination between different levels of complexity in quantum many-body systems.
Abstract: The control of quantum states is essential both for fundamental investigations a ...The control of quantum states is essential both for fundamental investigations and for technological applications of quantum physics. In quantum few-body systems, decoherence arising from interaction with the environment hinders the realization of desired processes. In quantum many-body systems, complexity of their dynamics further makes state preparation via external manipulation highly non-trivial. An effective strategy to counter these effects is offered by quantum optimal control theory, exploiting quantum coherence to dynamically reach a desired goal with high accuracy even under limitations on resources such as time, bandwidth, and precision. In this talk I will: - introduce the quantum optimal control method we developed to this aim, the CRAB (Chopped Random Basis) algorithm, which is to date the only method that allows to perform optimal control of quantum many-body systems; - present experimental results obtained via its application to various physical systems, from quantum logical operations in solid-state quantum optics to quantum criticality in ultra-cold atoms, both in open-loop and in closed-loop feedback scenarios, with applications ranging from quantum interferometry with Bose-Einstein condensates on atom chips to magnetic field sensing in diamond NV centers and to the preparation of optical-lattice quantum registers for quantum simulation; - use these examples to illustrate the quantum speed limit, i.e. the maximum speed achievable for a given quantum transformation, and describe related effects of nonlinearity due to inter-particle interactions and more in general to dynamical complexity; - propose a way to characterise the latter in an information-theoretical fashion by the bandwidth of the optimized control pulses, as well as a conjecture about using this method for discrimination between different levels of complexity in quantum many-body systems.

AMO Special Seminar

Date:
24
Monday
April
2017
Lecture / Seminar
Time: 12:45-14:00
Title: Anderson localization in nanophotonic structures
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Hanan Herzig Sheinfux
Organizer: Department of Physics of Complex Systems
Abstract: Anderson localization is a cornerstone of our understanding of the interaction o ...Anderson localization is a cornerstone of our understanding of the interaction of light with disorder. But in the deep subwavelength regime, all photonic transport effects, including Anderson localization, become trivialized and effective medium theory should take over. This talk will present work on subwavelength disordered multilayer structures - stacks of dielectric layers, where each is layer has an average thickness of lambda/40 (experimentally) or lambda/1000 (theoretically). But rather than being a weak effect, localization in this regime dominates transport completely and induces a rich regime of transport where disorder can sometimes increase transmission rather than reduce it. Furthermore, changing a single layer by 2 nm is shown to have a measurable effect on transport in visible wavelengths.

AMO Special Seminar

Date:
04
Tuesday
April
2017
Lecture / Seminar
Time: 13:15-14:15
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Prof. F. Ömer Ilday
Organizer: Department of Physics of Complex Systems
Abstract: Speakers: Gadi Afek, Dimitry Yankelev ...Speakers: Gadi Afek, Dimitry Yankelev

AMO Special Seminar

Date:
03
Monday
April
2017
Lecture / Seminar
Time: 13:00-14:00
Title: From Optical Clocks to Nano-Friction in Ion Coulomb Crystals
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Dr. Tanja E. Mehlstäubler
Organizer: Department of Physics of Complex Systems
Abstract: Time and frequency are the most accurately measurable quantities in physics. Wit ...Time and frequency are the most accurately measurable quantities in physics. With relative frequency inaccuracies as low as 10-18, optical clocks open up a new field of search for deviations in the predictions of Einstein’s general relativity, tests of modern unifying theories and the development of new sensors for gravity and navigation. However, in order to exploit their full potential, optical ion clocks need to integrate over many days to weeks. Scaling up the number of ions for optical clock spectroscopy is a natural way to significantly reduce the integration time, but was hindered so far by the poor control of the dynamics of coupled many body systems. Our research aims to use ion Coulomb crystals, i.e. many-body systems with complex dynamics, for precision spectroscopy. We have developed scalable linear ion traps with reduced axial micromotion to store multiple ions for clock spectroscopy. Linear chains of 115In+ ions are sympathetically cooled by 172Yb+ ions. Using resolved sideband spectroscopy on the narrow 2S1/2 → 2D5/2 transition in 172Yb+, we have characterized our ion trap for optical clock operation with systematic frequency uncertainties below 10-19. Storing large ion Coulomb crystals with a high level of control enables us to study many-body physics with trapped ions. The realization of topological defects in 2D crystals opens up a new research field of non-equilibrium dynamics and nonlinear physics in ion Coulomb crystals. We will present recent results on the study of tribology and transport in such a system.

AMO Special Seminar

Date:
02
Sunday
April
2017
Lecture / Seminar
Time: 10:15-11:30
Title: Quantum limits of sensing and imaging: Fundamental science while developing technology
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Prof. Animesh Datta
Organizer: Department of Physics of Complex Systems
Abstract: Seeking technological application of quantum information science is a widespread ...Seeking technological application of quantum information science is a widespread predilection at the present, particularly in sensing and imaging. Yet, most of the efforts have been limited to a single phase estimation problem, which very few practical applications are. I will show how our attempts to harness the technological potentials of quantum sensing and imaging in its full generality is leading us towards a better understanding of quantum mechanics.

AMO Special Seminar

Date:
28
Tuesday
March
2017
Lecture / Seminar
Time: 13:15-14:15
Title: Towards scalable quantum photonics via light storage
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Dr. Joshua Nunn
Organizer: Department of Physics of Complex Systems
Abstract: Photonics is the only platform for quantum information processing with the poten ...Photonics is the only platform for quantum information processing with the potential to operate at room temperature, in ambient conditions, without the need for cryogenics, high vacuum or electromagnetic shielding. But it cannot be scaled up because logical operations in linear optics are fundamentally non-deterministic. My research has focussed on a route to scalable photonics by actively synchronising successful operations with quantum memories — devices that can store and release photons on-demand. In this talk I will review our approach to this challenge and present our most recent results demonstrating noise-free storage of GHz-bandwidth heralded single photons in warm vapour.

AMO Special Seminar

Date:
21
Tuesday
March
2017
Lecture / Seminar
Time: 13:15-14:15
Title: The delay-time distribution in scattering of ultra-short light pulses from complex targets
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Prof. Uzy Smilansky
Organizer: Department of Physics of Complex Systems
Abstract: When time-narrow wave-packets scatter by complex target, the field is trapped f ...When time-narrow wave-packets scatter by complex target, the field is trapped for some time, and emerges as a time broadened pulse, whose shape reflects the distribution of the delay (trapping) -times. I shall present a comprehensive framework for the computation of the delay-time distribution, and its dependence on the scattering dynamics, the wave-packet envelope (profile) and the dispersion relation. I shall then show how the well-known Wigner-Smith mean delay time and the semi-classical approximation emerge as limiting cases, valid only under special circumstances. For scattering on random media, localization has a drastic effect on the delay-time distribution. I shall demonstrate it for a particular one-dimensional system which can be analytically solved.

Evaluating the Role of Water Availability in Determining the Yield/Plant Population Density Relationship

Date:
21
Tuesday
March
2017
Lecture / Seminar
Time: 11:15
Location: Ullmann Building of Life Sciences
Lecturer: Dr. Shmulik Friedman
Organizer: Department of Plant and Environmental Sciences
Details: Homepage:http://www.agri.gov.il/en/people/683.aspx
Abstract: Thirty-eight yield/plant-population-density (Y-PPD) data sets were collected fro ...Thirty-eight yield/plant-population-density (Y-PPD) data sets were collected from the literature and analyzed statistically to yield, inter alia, a single "universal" relationship that realistically describes the Y-PPD data obtained with various plants in various agricultural and environmental conditions. The present study aims to facilitate evaluation of the dependence of water availability to plant-root systems on plant-population density, plant-arrangement geometry, active-root-system size, and soil texture. The outlined evaluation of the relative water uptake rate/plant-population-density (RWUR-PPD) relationship can quantify the roles of water availability and competition among neighboring root systems in determining the Y-PPD relationship. In particular, this methodology quantifies the effects of root system size, soil capillary length and planting rectangularity, on the Y-PPD relationship. Overall, the proposed RWUR evaluation shows, in reasonable qualitative agreement with experimental findings, that the Y-PPD relationship increases with increasing root system radius and soil capillary length, and with decreasing rectangularity. RWUR evaluation shows that interplant competition for water increases approximately linearly with the product of (root-system radius) × (soil capillary length). The water-competition factor is approximately equal to 4 r01-1, i.e. to the surface area of a sphere with a radius equal to the geometric mean of the radius of root system (r0) and the soil capillary length (-1). Plant roots and shoots compete also for resources other than water, e.g., soil nutrients and oxygen and solar radiation. Thus, the agronomically important Y-PPD relationship depends on genetic, agricultural, and environmental factors that affect availability of other resources differently from their effects on water availability; and these differences render it virtually impossible to define and quantify the roles of the various essential resources and the effects of diverse factors in determining the Y-PPD relationship. This is why practical agronomists use empirical mathematical expressions to describe Y-PPD.

Chemical Physics Department Guest Seminar

Date:
15
Wednesday
March
2017
Lecture / Seminar
Time: 10:00
Title: Thermalization, Dynamics and Many-Body Localization
Location: Gerhard M.J. Schmidt Lecture Hall
Lecturer: Dr Yevgeny Bar Lev
Organizer: Department of Chemical and Biological Physics
Abstract: Remarkably, a generic interacting system with many degrees of freedom is often w ...Remarkably, a generic interacting system with many degrees of freedom is often well described by a random matrix drawn from an appropriate ensemble, which solely relies on the symmetries of the system. This is one of the central premises of quantum chaos theory which explains the fascinating universality of statistical properties of eigenvalues and eigenstates of generic systems. Such systems, slightly pushed out-of-equilibrium, are normally expected to relax diffusively. In this talk I will show that disordered and interacting systems which exhibit a many-body localization (MBL) transition, behave in a strikingly different manner than expected from the above tenets in both one dimensional [1,2] and two dimensional systems [3]. These systems thermalize subdiffusively, have a vanishing diffusion coefficient and cannot be described by usual random matrix ensembles [4]. I will show the implications of these results on thermalization in closed quantum systems, and will derive a general relation between statistical properties of matrix elements of physical observables and a dynamical property of the system [4]. I will finish my talk by presenting some promising future directions [5].

AMO Journal Club

Date:
14
Tuesday
March
2017
Lecture / Seminar
Time: 13:15-14:30
Location: Edna and K.B. Weissman Building of Physical Sciences
Organizer: Department of Physics of Complex Systems
Abstract: Speakers: Chene Tradonsky, Dr. Vishwa Pal ...Speakers: Chene Tradonsky, Dr. Vishwa Pal

"Hydrodynamics of one-dimensional particle systems"

Date:
13
Monday
March
2017
Lecture / Seminar
Time: 14:15
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Harald A. Posch
Organizer: Department of Physics of Complex Systems
Abstract: One-dimensional particle systems are known to be anomalous with respect to the ...One-dimensional particle systems are known to be anomalous with respect to the dynamics of their hydrodynamic conserved fields and their related currents. We review some of the predictions of mode-mode coupling theory and of exact results by Prähofer and Spohn [J. Stat. Phys., vol. 115, 255 (2004)] to derive asymptotic expressions for the time-correlation functions of the hydrodynamic modes and their currents. These results are compared to extensive computer simulations for two simple fluids with non-linear short-range interactions.

Molecular semiconductors for LEDs and solar cells: designing around the Coulomb interaction

Date:
09
Thursday
March
2017
Lecture / Seminar
Time: 11:00-12:00
Location: Perlman Chemical Sciences Building
Lecturer: Prof. Richard Friend
Organizer: Department of Materials and Interfaces
Details: Pi-conjugated organic molecules and polymers now provide a set of well-performing semiconductors that support devices, including light-emitting diodes (LEDs) as used in smart-phone displays and lighting, field-effect transistors (FETs) and photovoltaic diodes (PVs). These are attractive materials to manufacture, particularly for large-area applications where they can be processed by direct printing, so that the cost of materials and processing can be very low. This practical success is made possible by breakthroughs in the understanding and engineering of the underlying semiconductor science. The physics of organic semiconductors is often controlled by large electron-hole Coulomb interactions and by large spin exchange energies. Management of excited state spin is fundamental for efficient LED and solar cells operation. I will discuss in particular recent progress in the control of emissive spin singlet excited states and non-emissive spin triplet excited states.

"Surface studies and matter wave optics experiments with neutral helium beams"

Date:
06
Monday
March
2017
Colloquium
Time: 11:00-12:15
Location: Gerhard M.J. Schmidt Lecture Hall
Lecturer: Prof. Bodil Holst
Organizer: Faculty of Chemistry

Chemical Physics Department Guest Seminar

Date:
05
Sunday
March
2017
Lecture / Seminar
Time: 11:00
Title: TEERs for DEERs - advanced spectroscopy of correlated spins in molecules using a single spin sensor‎
Location: Gerhard M.J. Schmidt Lecture Hall
Lecturer: Dr Amit Finkler
Organizer: Department of Chemical and Biological Physics
Abstract: Defects in the solid state are potentially suitable candidates for nanoscale sen ...Defects in the solid state are potentially suitable candidates for nanoscale sensing and imaging. Among these, the nitrogen-vacancy (NV) center in diamond has gained wide publicity due to its long coherence time, stability and wide temperature and frequency ranges of operation. With recent reports on the sensing of electron and nuclear spins from single proteins, we attempt to go one step further to the realm of correlated spins. I will present measurements of electron spins in spin-labeled molecules both at room temperature and at low temperature. I will show that it is possible to detect the dipolar coupling between two spin labels in a doubly-labeled peptide using a scheme we call "triple electron-electron resonance". This is a necessary step towards sensing of spins in correlated-electrons systems. Together with quantum-assisted schemes and improvements in signal readout, I will offer methods with which we can tackle challenges in chemical physics, laying out a potential platform for a spin network.

FRISNO14

Date:
05
Sunday
March
2017
Conference
Time: 08:00-15:00
Location: David Lopatie Conference Centre

AMO Special Seminar

Date:
02
Thursday
March
2017
Lecture / Seminar
Time: 14:00-15:30
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Dr. Tracy Northup
Organizer: Department of Physics of Complex Systems

AMO Special Seminar

Date:
01
Wednesday
March
2017
Lecture / Seminar
Time: 13:15-14:15
Title: Attosecond charge transport in atoms and condensed matter
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Prof. Ursula Keller
Organizer: Department of Physics of Complex Systems
Abstract: The basic motivation for our work is to understand how charge is transported on ...The basic motivation for our work is to understand how charge is transported on an atomic spatial and attosecond time scale. Strong-field ionization in the dipole approximation (i.e. tunnel ionization) is much faster than the group delay of the electron wavepacket (i.e. Wigner delay), whereas photoemission from atoms can typically be described by the Wigner delay - but not in all cases. For example autoionization resonances in the continuum can change the ionization delay. Moving to condensed matter we have investigated the escape time of photoemitted electrons from metal surfaces such as Ag, Au and Cu. We want to address the question about the correct escape velocity of the electons and their ability to “feel” the periodic crystal potential on a attosecond time and an atomic length scale. Our most recent experiment can confirm an upper limit of around 300 attosecond over a distance less than 2 atomic layers during which an electron can assume its effective mass. Furthermore femtosecond charge transport modulation driven by a transient electric field in the petahertz regime have been observed in diamond and can be explained by the dynamical Kranz Keldysh effect (DFKE). State-of-the-art numerical calculations reveal that only a small number of transitions give rise to the observed effects and that the more classical intra-band transitions dominate the response over inter-band transitions.

Chiral Quantum Optics

Date:
23
Thursday
February
2017
Colloquium
Time: 11:15-12:30
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Arno Rauschenbeutel
Organizer: Faculty of Physics
Details: 11:00 – coffee, tea, and more
Abstract: Controlling the interaction of light and matter is the basis for diverse applica ...Controlling the interaction of light and matter is the basis for diverse applications ranging from light technology to quantum information processing. Nowadays, many of these applications are based on nanophotonic structures. It turns out that the confinement of light in such nanostructures imposes an inherent link between its local polarization and its propagation direction, also referred to as spin–momentum locking of light [1]. Remarkably, this leads to chiral, i.e., propagation direction-dependent effects in the emission and absorption of light, and elementary processes of light–matter interaction are fundamentally altered. For example, when coupling plasmonic particles or atoms to evanescent fields, the intrinsic mirror symmetry of the particles’ emission can be broken. In our group, we observed this effect in the interaction between single rubidium atoms and the evanescent part of a light field that is confined by continuous total internal reflection in a whispering-gallery-mode microresonator [2]. In the following, this allowed us to realize chiral nanophotonic interfaces in which the emission direction of light into the structure is controlled by the polarization of the excitation light [3] or by the internal quantum state of the emitter [4], respectively. Moreover, we employed this chiral interaction to demonstrate an integrated optical isolator [5] as well as an integrated optical circulator [6] which operate at the single-photon level and which exhibit low loss. The latter are the first two examples of a new class of nonreciprocal nanophotonic devices which exploit the chiral interaction between single quantum emitters and transversally confined photons. References 1 K. Y. Bliokh, F. J. Rodríguez-Fortuño, F. Nori, and A. V. Zayats, Spin-orbit interactions of light, Nat. Photon. 9, 796 (2015). [2] C. Junge, D. O'Shea, J. Volz, and A. Rauschenbeutel, Strong coupling between single atoms and non-transversal photons, Phys. Rev. Lett. 110, 213604 (2013). [3] J. Petersen, J. Volz, and A. Rauschenbeutel, Chiral nanophotonic waveguide interface based on spin-orbit coupling of light, Science 346, 67 (2014). [4] R. Mitsch, C. Sayrin, B. Albrecht, P. Schneeweiss, and A. Rauschenbeutel, Quantum state-controlled directional spontaneous emission of photons into a nanophotonic waveguide, Nature Commun. 5, 5713 (2014). [5] C. Sayrin, C. Junge, R. Mitsch, B. Albrecht, D. O'Shea, P. Schneeweiss, J. Volz, and A. Rauschenbeutel, Nanophotonic Optical Isolator Controlled by the Internal State of Cold Atoms, Phys. Rev. X 5, 041036 (2015). [6] M. Scheucher, A. Hilico, E. Will, J. Volz, and A. Rauschenbeutel, Quantum optical circulator controlled by a single chirally coupled atom, Science 354, 1577 (2016).

AMO Special Seminar

Date:
21
Tuesday
February
2017
Lecture / Seminar
Time: 13:15-14:15
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Dr. August Krueger
Organizer: Department of Physics of Complex Systems
Abstract: Consider the correspondence f(x,y) → f(X,Y), where f is a function, x,y  ...Consider the correspondence f(x,y) → f(X,Y), where f is a function, x,y ∈ ℜ are coordinates, and X,Y are linear operators on an auxiliary space that satisfy the commutation relation XY-YX=i ∈ ℑ, for some real number ε. Making sense of f(X,Y) can require great care. In physics one encounters this problem with the phase space picture of quantum mechanics commonly used in quantum optics, where X,Y are conjugate position and momentum operators. Such notions also occur in the strong field limit of the Landau problem and its string theory equivalent for D-branes where X,Y are the position operators for coordinates in a spatial plane. In mathematics one finds these problems addressed by harmonic analysis on the Heisenberg group along with general pseudo-differential operators and symbol calculus. The ubiquity of the f(x,y) → f(X,Y) question has led many researchers in many different fields to perennially rediscover some formulas and miss others. This talk will discuss a review paper which aims to help the disparate communities speak to one another and cover new ground. This talk will focus on explicit representations and useful formulas. We will emphasize otherwise unexpected correspondences between continuous PDE and lattice difference equations, the likes of which are often found in models of nonlinear optical waveguide array lattices.

AMO PhD Defense

Date:
20
Monday
February
2017
Lecture / Seminar
Time: 11:15-12:15
Title: Ultrasensitive measurements with high-Q toroidal micro-resonators
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Yulia Lovsky
Organizer: Department of Physics of Complex Systems

Mass Transfer in Binaries:Planets Around Stars and Stars Around Supermassive Black Holes

Date:
16
Thursday
February
2017
Colloquium
Time: 11:15-12:30
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Reem Sari
Organizer: Faculty of Physics
Details: 11:00 – coffee, tea, and more
Abstract: Mass transfer between members of a binary is a common and well studies situation ...Mass transfer between members of a binary is a common and well studies situation. As members of a binary become closer to each other, mass may leak from one object due to the strong tidal forces from the other. Usually, the leaking mass flows towards the companion, but we show that for main sequence stars that orbit the supermassive black hole in the galactic center and emit gravitational waves mass may also leak away from it. We show that the mass transfer affects the evolution of the gravitational wave emission in a way that reflects internal properties of the star. This may be relevant to observations of the planned LISA mission. On another front, tides may lead to orbital decay of planets which are close enough to their stars. Mass transfer will occur and we discuss its observational consequences in view of data from the Kepler mission.

AMO Journal Club

Date:
14
Tuesday
February
2017
Lecture / Seminar
Time: 13:15-14:30
Location: Edna and K.B. Weissman Building of Physical Sciences
Organizer: Department of Physics of Complex Systems
Abstract: Speakers: Omri Bar-Elli, Ayelet Uzan ...Speakers: Omri Bar-Elli, Ayelet Uzan

The information revolution, nano-physics and quantum mechanics

Date:
12
Sunday
February
2017
Lecture / Seminar
Time: 11:00-12:30
Title: The annual open Amos De-Shalit lecture
Location: Michael and Anna Wix Auditorium
Lecturer: Prof. Moty Heiblum
Organizer: Science for All Unit
Details: * will be held in Hebrew

Novel quantum oscillatory phenomena of Weyl and Dirac materials

Date:
09
Thursday
February
2017
Colloquium
Time: 11:15-12:30
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: James Analytis
Organizer: Faculty of Physics
Details: 11:00 – coffee, tea, and more
Abstract: The discovery of topological insulators, Weyl and Dirac materials, has been argu ...The discovery of topological insulators, Weyl and Dirac materials, has been arguably the most exciting development in condensed matter physics in decades. It has lead to a resurgence of interest in the role of topological quantum numbers in not only understanding but also classifying certain kinds of solids, akin to how symmetry has been used to classify properties of solids. Weyl and Dirac materials have been predicted to have extraordinary properties, particularly in their transport. In this talk I discuss some transport and magnetic signatures revealed in quantum oscillatory phenomena that may provide a pathway to identify and apply these exotic materials.

AMO Journal Club

Date:
07
Tuesday
February
2017
Lecture / Seminar
Time: 13:15-14:30
Location: Edna and K.B. Weissman Building of Physical Sciences
Organizer: Department of Physics of Complex Systems
Abstract: Speakers: Gal Orenstein, Arnaud Courvoisier ...Speakers: Gal Orenstein, Arnaud Courvoisier

QUANTUM FIELD THEORIES OF (N-1)-DIMENSIONAL EXTENDED OBJECTS IN 2N-DIMENSIONAL SPACE-TIME MANIFOLDS AS 2D QUANTUM FIELD THEORIES ON ``QUASI RIEMANN SURFACES'' OF INTEGRAL (N-1)-CURRENTS.

Date:
07
Tuesday
February
2017
Lecture / Seminar
Time: 10:00
Lecturer: DANIEL FRIEDAN
Organizer: Department of Particle Physics and Astrophysics
Details: 09:50 Gathering and coffee
Abstract: Abstract: In my talk I will discuss some new features of conformal anomaly an ... Abstract: In my talk I will discuss some new features of conformal anomaly and entanglement entropy in the presence of boundaries. The talk is based on recent papers.This is a project to develop a wide expanse of new quantum field theories in 2n-dimensional space-time manifolds. For each 2d qft, there is to be a qft of extended objects in every 2n-dimensional space-time manifold M. The quantum fields live on ``quasi Riemann surfaces'', which are certain spaces of integral (n-1)-currents in M. The notion of integral current comes from Geometric Measure Theory. The quasi Riemann surfaces are complete metric spaces with analytic properties strictly analogous to Riemann surfaces. The new qfts are to be constructed on the quasi Riemann surfaces just as 2d qfts are constructed on ordinary Riemann surfaces. Local fields in space-time are obtained by restricting to small extended objects. arXiv:1510.04566, arXiv:1601.06418 and arXiv:1604.07571

"Imaging wave function of few body systems: He dimers, trimers and the Efimov state of He3"

Date:
06
Monday
February
2017
Colloquium
Time: 11:00-12:15
Location: Gerhard M.J. Schmidt Lecture Hall
Lecturer: Prof. Reinhard Doerner
Organizer: Faculty of Chemistry
Abstract: Two and three Helium atoms form very unusual and extreme quantum systems. Their ...Two and three Helium atoms form very unusual and extreme quantum systems. Their typical extend is ten to hundred times bigger than radius of the atoms, the wavefunction lives almost completely in the classically forbidden tunneling region and the binding energy of these systems is about 8 orders of magnitude smaller than that of a normal molecule. We will show how coincidence detection of charged fragments and super strong laser fields can be used to image the wave functions of these Helium quantum giants and will show the first experimental images of an Efimov state.

Theory Excellence Center Seminar

Date:
01
Wednesday
February
2017
Lecture / Seminar
Time: 11:00-12:00
Title: Solving the Problem of Anharmonic Densities of States
Location: Gerhard M.J. Schmidt Lecture Hall
Lecturer: Prof. Julius Jellinek
Organizer: Department of Chemical and Biological Physics
Abstract: Solving the Problem of Anharmonic Densities of States* Julius Jellinek Ch ...Solving the Problem of Anharmonic Densities of States* Julius Jellinek Chemical Sciences and Engineering Division Argonne National Laboratory, Argonne, IL 60439, USA Density of states (DOS) is a fundamental characteristic of systems that lies in the very foundation of statistical mechanics and all the theoretical constructs that derive from them (e.g., kinetic rate theories, phase diagrams, etc.). Knowledge of DOS is central for calculation of entropy, partition function, free energy, reaction rate constants, and other important characteristics. The accuracy of all these depends on the accuracy with which the DOS is defined. Even though virtually all real systems are anharmonic, the current practice in the computation of vibrational DOSs is largely based on the harmonic approximation. The reason is that despite major efforts over about eight decades a general and exact, yet practical in applications, solution to the problem of anharmonic DOSs stubbornly resisted resolution. The alternatives introduced are mostly limited to cases of weak anharmonicity and/or suffer from other shortcomings. In a recent development, we formulated a general and exact solution to this long-standing problem, which is applicable to arbitrary degree of anharmonicity (i.e., any system) and that is practical and efficient in applications. The solution and its algorithmic implementations are developed within the frameworks of both classical and quantum mechanics. The quantum implementation involves generalization and significant enhancement in the efficiency of the celebrated Beyer-Swinehart counting scheme, which is the fastest to date algorithm used in the computation of the quantum harmonic DOSs. Our solution is based on simulating the actual dynamical behavior of systems on the time scale of interest, short or long, as defined by the experiment and/or the nature of the process or phenomenon at hand. As a consequence, the resulting anharmonic DOSs are fully dynamically informed and, in general, time-dependent. As such, they lay the foundation for formulation of new statistical mechanical frameworks that incorporate time and reproduce exactly the actual time-averaged dynamical behavior of systems on the temporal scale of interest irrespective of whether this behavior is statistical or not in the traditional sense. Work has been initiated on extending this development to the general case of rotational(ro)-vibrational DOSs for systems with arbitrary degree of anharmonicity and arbitrarily strong ro-vibrational coupling. ---------------- * This work was supported by the Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences and Biosciences, U.S. Department of Energy under Contract No. DE-AC02-06CH11357.

Foundations of Computer Science Seminar

Date:
23
Monday
January
2017
Lecture / Seminar
Time: 14:30-16:00
Title: The FedEx Problem
Location: Jacob Ziskind Building
Lecturer: Kira Goldner
Organizer: Faculty of Mathematics and Computer Science
Abstract: Consider the following setting: a customer has a package and is willing to pay u ...Consider the following setting: a customer has a package and is willing to pay up to some value v to ship it, but needs it to be shipped by some deadline d. Given the joint prior distribution from which (v, d) pairs are drawn, we characterize the auction that yields optimal revenue, contributing to the very limited understanding of optimal auctions beyond the single-parameter setting. Our work further demonstrates the importance of 'ironing' in revenue maximization, helping to illustrate why randomization is necessary to achieve optimal revenue. Finally, we strengthen the emerging understanding that duality is useful for both the design and analysis of optimal auctions in multi- parameter settings. Joint work with Amos Fiat, Anna Karlin, and Elias Koutsoupias.

From single-particle to many-body Anderson localization

Date:
19
Thursday
January
2017
Colloquium
Time: 11:15-12:30
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Alexander Mirlin
Organizer: Faculty of Physics
Details: 11:00 – coffee, tea, and more
Abstract: It was shown in Anderson’s famous paper “Absence of diffusion in certain ran ...It was shown in Anderson’s famous paper “Absence of diffusion in certain random lattices" in 1958 that a sufficiently strong disorder completely localizes a quantum particle. More recently, it was understood that Anderson localization may take place also in interacting many-body systems at non-zero temperature—the phenomenon that is termed “many-body localization”. In this talk, I will review underlying theoretical ideas and will discuss effects that may limit experimental observation of many-body localization.

Prof. Ronny Neumann - Solar fuels -Where are we and where are we headed?

Date:
17
Tuesday
January
2017
Lecture / Seminar
Time: 12:00-13:00
Location: Dolfi and Lola Ebner Auditorium
Lecturer: Prof. Ronny Neumann
Organizer: Department of Media Relations
Details: The lecture is in Hebrew

Hot gas in clusters of galaxies, cosmic microwave background radiation and cosmology

Date:
12
Thursday
January
2017
Colloquium
Time: 11:15-12:30
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Rashid Sunyaev
Organizer: Faculty of Physics
Details: 11:00 – coffee, tea, and more
Abstract: Presence of the hot (kTe ~ 3 - 10 KeV) rarefied gas in the clusters of galaxies ...Presence of the hot (kTe ~ 3 - 10 KeV) rarefied gas in the clusters of galaxies (most massive gravitationally bound objects in the Universe) leads to the appearance of "shadows" in the angular distribution of the Cosmic Microwave Background (CMB) Radiation and permits to measure the peculiar velocities of these clusters relative to the unique coordinate frame where CMB is isotropic. I plan to describe the physics leading to these observational effects. Planck spacecraft, ground based South Pole and Atacama Cosmology Telescopes discovered recently more than thousand of unknown before Clusters of Galaxies at high redshifts detecting these "shadows" and traces of kinematic effect, demonstrating the correlation of the hot gas velocities with mass concentrations on large scales. Giant ALMA submillimeter interferometer in Atacama desert resolved recently strong shocks between merging clusters of galaxies. Newly discovered clusters of galaxies permit to study the rate of growth of the large scale structure of the Universe and open an independent way to measure key cosmological parameters of our Universe. I plan to mention Russian - German Spectrum-X/eRosita space mission under preparation for the launch in the March of 2018. This mission will be able to detect all (hundred thousand !) rich clusters of galaxies in the observable Universe and up to 3 millions of accreting supermassive black holes (in Active Galactic Nuclei) during 4 year long X-Ray sky survey. S3 and S4 ground based CMB research programs promise to reach similar or even higher sensitivities and detect up to a million of clusters and groups of galaxies containing hot gas.

Algebraic Geometry and Representation Theory Seminar

Date:
10
Tuesday
January
2017
Lecture / Seminar
Time: 11:15-12:30
Title: Finite-dimensional representations of quantum affine algebras
Location: Jacob Ziskind Building
Lecturer: Jianrong Li
Organizer: Faculty of Mathematics and Computer Science
Abstract: I will talk about finite dimensional representations of quantum affine algebras. ...I will talk about finite dimensional representations of quantum affine algebras. The main topics are Chari and Pressley's classification of finite-dimensional simple modules over quantum affine algebras, Frenkel and Reshetikhin's theory of q-characters of finite dimensional modules, Frenkel-Mukhin algorithm to compute q-characters, T-systems, Hernandez-Leclerc's conjecture about the cluster algebra structure on the ring of a subcategory of the category of all finite dimensional representations of a quantum affine algebra. I will also talk about how to obtain a class of simple modules called minimal affinizations of types A, B using mutations (joint work with Bing Duan, Yanfeng Luo, Qianqian Zhang).

The Snowball Bifurcation on Exoplanets

Date:
08
Sunday
January
2017
Lecture / Seminar
Time: 11:00
Location: Sussman Family Building for Environmental Sciences
Lecturer: Dr. Dorian Abbot
Organizer: Department of Earth and Planetary Sciences
Abstract: The Snowball Earth episodes may have affected the development of life on Earth t ...The Snowball Earth episodes may have affected the development of life on Earth through increasing atmospheric oxygen and spurring evolution. Considering the habitability and increase in complexity of life on other planets therefore requires thought about Snowball climate states. Using an energy balance model and global climate model, I will show that it is unlikely a tidally locked planet could experience a Snowball Earth bifurcation. Instead the planet would smoothly transition to global ice coverage. This is due to the difference in the shape of the insolation, which increases strongly toward the substellar point on a tidally locked planet. I will then change focus slightly and explain how climate oscillations between a warm state and a Snowball state can occur on a planet within the habitable zone that has a small CO2 outgassing rate. I will develop analytical relations to understand these cycles and outline scalings in variables such as the cycle period as a function of important climatic and weathering parameters. Work of this type should help us understand the context of planetary habitability and focus on appropriate targets as we seek to find the first inhabited exoplanet.

Gamma-ray astronomy - observing the extreme places in the Universe

Date:
05
Thursday
January
2017
Colloquium
Time: 11:15-12:30
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Christian Stegmann
Organizer: Faculty of Physics
Details: 11:00 – coffee, tea, and more
Abstract: Astronomy with gamma rays at energies above some 10 GeV has opened in the last d ...Astronomy with gamma rays at energies above some 10 GeV has opened in the last decade a new window to the cosmos. Gamma rays allows us to take a look at the extreme places in our Universe. They are produced in Supernova remains, Black holes and active galaxies - cosmic particle accelerators, in which atomic nuclei and electrons are accelerated to vast energies. Contrary to expectations high-energy phenomena are no exception in the cosmos, but occur in many galactic and extragalactic objects during their life cycle. There are currently over 2000 sources of GeV radiation and over 150 sources of TeV radiation. Thus the results of gamma astronomy are an important building block to the understanding of the development of the Milky Way and our Universe. So far, gamma-ray astronomy in the TeV range, however, is performed with experiments that are only accessible to a limited circle of users. With the Cherenkov Telescope Array CTA an international consortium of more than 1000 scientists and engineers aims for an open observatory. Starting from the current findings of gamma-ray astronomy I will in the presentation date to look into the future to what we will be able to learn with CTA.

"A Collective Quartic for the Composite Higgs from 6d"

Date:
04
Wednesday
January
2017
Lecture / Seminar
Time: 13:00
Lecturer: Michael Geller
Organizer: Department of Particle Physics and Astrophysics
Details: 10:45 Coffee 12:15 Lunch
Abstract: a Pseudo-Nambu-Goldstone boson (PNGB) and the resulting Higgs properties deviate ...a Pseudo-Nambu-Goldstone boson (PNGB) and the resulting Higgs properties deviate from those predicted by the SM. The current Higgs and EW data favor a SM-like Higgs, requiring a hierarchy between the PNGB Higgs decay constant f and its vacuum expectation value v. The v/f hierarchy is responsible for a significant part of the fine-tuning in these models. We show that adding an independent, adjustable quartic to the Higgs potential can eliminate the v/f tuning, such that the only remaining tuning arises from radiative corrections to the Higgs mass. We demonstrate how this quartic can be obtained from extra-dimensions, revisiting the 6d origin of the little-Higgs models, this time in a warped AdS5xS1 background. We construct a 6D Composite Higgs model and also consider its deconstruction into a two-site Randall-Sundrum model. The PNGB Higgs in this model corresponds to the extra-dimensional components of a gauge field, and the quartic arises from the non-abelian gauge action in 6d. We show that this quartic is collective just like in little Higgs models, and so it is stable against quantum corrections. Our quartic scales like (R6/R), where R6 is the size of the flat circle, and R is the curvature radius of AdS. We show that a general hierarchy of (R6/R) can be naturally stabilized, and any desired quartic can be obtained.

Faculty of Chemistry Theory Excellence Center Seminar

Date:
02
Monday
January
2017
Lecture / Seminar
Time: 11:00
Title: The self-consistent phonons method and its applications to computation of equilibrium and dynamical properties of molecules and clusters
Location: Gerhard M.J. Schmidt Lecture Hall
Lecturer: Prof. Vladimir Mandelshtam
Organizer: Department of Chemical and Biological Physics
Abstract: The self-consistent phonons (SCP) method is a practical approach for computing s ...The self-consistent phonons (SCP) method is a practical approach for computing structural and dynamical properties of a general quantum or classical many-body system while incorporating anharmonic effects. In SCP one finds an effective temperature-dependent harmonic Hamiltonian that provides the “best fit” for the physical Hamiltonian, the “best fit” being defined as the one that optimizes the Helmholtz free energy at a fixed temperature. The numerical bottleneck of the method is the evaluation of Gaussian averages of the potential energy and its derivatives. Several algorithmic ideas/tricks are introduced to reduce the cost of such integration by orders of magnitude, e.g., relative to that of the previous implementation of the SCP approach by Calvo et al. [J. Chem. Phys. 133, 074303 (2010)]. One such algorithmic improvement is the replacement of standard Monte Carlo integration by quasi-Monte Carlo integration utilizing low-discrepancy sequences. SCP has been used to study the equilibrium properties and the structural transitions in small and large Lennard-Jones clusters. The method was also applied to computations of vibrational spectra of water clusters.

High energy neutrino and cosmic-ray astrophysics: The way forward

Date:
02
Monday
January
2017
-
15
Sunday
January
2017
Conference
Time: 08:00
Location: Edna and K.B. Weissman Building of Physical Sciences

From Black Holes to Bad Metals

Date:
29
Thursday
December
2016
Colloquium
Time: 11:15-12:30
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Sean hartnoll
Organizer: Faculty of Physics
Details: 11:00 – coffee, tea, and more
Abstract: Electrical and thermal transport in unconventional materials such as "bad metals ...Electrical and thermal transport in unconventional materials such as "bad metals” continues to pose tough challenges for theory. I will argue that a promising approach to understanding the properties of these materials is through the notion of fundamental quantum bounds on certain observables, that can apply independently of the microscopic dynamics. Some evidence for such bounds has come from the study of black holes, which have been argued to be the “most extreme” of all physical systems in various senses that I will discuss. In particular, the diffusion of energy across a black hole event horizon shares important features in common with the transport of energy and change in a bad metal.

Second-law-like constraints on higher energy moments in small open quantum systems

Date:
26
Monday
December
2016
Lecture / Seminar
Time: 14:15
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Raam Uzdin
Organizer: Department of Physics of Complex Systems
Abstract: Quantum thermodynamics deals with thermodynamic effects and thermodynamic constr ...Quantum thermodynamics deals with thermodynamic effects and thermodynamic constraints (e.g. the 2nd law) that emerge in out-of-equilibrium microscopic open quantum systems, and in microscopic heat machines. Presently, the technology developed for quantum computing is sufficient for exploring quantum thermodynamic experimentally (new experimental results will be shown). On top of the second law, thermodynamic resource theory predicts additional mathematical constraints on thermal transformation of microscopic systems. Unlike the second law, these constraints cannot be related to thermodynamic observables. Consequently, they are useful for some theoretical purposes, but not for making concrete predictions on realistic scenarios. In this talk I will present a new formalism that yields additional “seconds laws” that follow the logic and structure of the standard 2nd law. While the 2nd law deals with the first moment of the energy (average heat, average work), the observables in the new laws are higher moments of the energy. I will show several scenarios where these laws provide concrete answers to “blind spots” that are not addressed by the standard 2nd law. In other cases tighter bounds are obtained compared to the standard 2nd law. Potentially, this formalism can significantly extend the thermodynamic framework, and put additional practical bounds on thermal transformations and microscopic heat machines. Finally, I will discuss the connection to quantum coherence measures and list several research directions.

Second-law-like constraints on higher energy moments in small open quantum systems

Date:
26
Monday
December
2016
Lecture / Seminar
Time: 14:15
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Raam Uzdin
Organizer: Department of Physics of Complex Systems
Abstract: Quantum thermodynamics deals with thermodynamic effects and thermodynamic constr ...Quantum thermodynamics deals with thermodynamic effects and thermodynamic constraints (e.g. the 2nd law) that emerge in out-of-equilibrium microscopic open quantum systems, and in microscopic heat machines. Presently, the technology developed for quantum computing is sufficient for exploring quantum thermodynamic experimentally (new experimental results will be shown). On top of the second law, thermodynamic resource theory predicts additional mathematical constraints on thermal transformation of microscopic systems. Unlike the second law, these constraints cannot be related to thermodynamic observables. Consequently, they are useful for some theoretical purposes, but not for making concrete predictions on realistic scenarios. In this talk I will present a new formalism that yields additional “seconds laws” that follow the logic and structure of the standard 2nd law. While the 2nd law deals with the first moment of the energy (average heat, average work), the observables in the new laws are higher moments of the energy. I will show several scenarios where these laws provide concrete answers to “blind spots” that are not addressed by the standard 2nd law. In other cases tighter bounds are obtained compared to the standard 2nd law. Potentially, this formalism can significantly extend the thermodynamic framework, and put additional practical bounds on thermal transformations and microscopic heat machines. Finally, I will discuss the connection to quantum coherence measures and list several research directions.

Chemical Physics Department Guest Seminar

Date:
21
Wednesday
December
2016
Lecture / Seminar
Time: 10:00
Title: Second-law-like constraints on higher energy moments in small open quantum systems
Location: Gerhard M.J. Schmidt Lecture Hall
Lecturer: Dr Raam Uzdin
Organizer: Department of Chemical and Biological Physics
Abstract: Quantum thermodynamics deals with thermodynamic effects and thermodynamic constr ...Quantum thermodynamics deals with thermodynamic effects and thermodynamic constraints (e.g. the 2nd law) that emerge in out-of-equilibrium microscopic open quantum systems, and in microscopic heat machines. Presently, the technology developed for quantum computing is sufficient for exploring quantum thermodynamic experimentally (new experimental results will be shown). On top of the second law, thermodynamic resource theory predicts additional mathematical constraints on thermal transformation of microscopic systems. Unlike the second law, these constraints cannot be related to thermodynamic observables. Consequently, they are useful for some theoretical purposes, but not for making concrete predictions on realistic scenarios. In this talk I will present a new formalism that yields additional “seconds laws” that follow the logic and structure of the standard 2nd law. While the 2nd law deals with the first moment of the energy (average heat, average work), the observables in the new laws are higher moments of the energy. I will show several scenarios where these laws provide concrete answers to “blind spots” that are not addressed by the standard 2nd law. In other cases tighter bounds are obtained compared to the standard 2nd law. Potentially, this formalism can significantly extend the thermodynamic framework, and put additional practical bounds on thermal transformations and microscopic heat machines. Finally, I will discuss the connection to quantum coherence measures and list several research directions.

AMO Special Seminar

Date:
13
Tuesday
December
2016
Lecture / Seminar
Time: 13:15-14:15
Title: Quantum Logic Spectroscopy of Trapped Ions
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Piet O. Schmidt
Organizer: Department of Physics of Complex Systems
Details: Falafel in the lobby at 12:50
Abstract: Precision spectroscopy is a driving force for the development of our physical un ...Precision spectroscopy is a driving force for the development of our physical understanding. However, only few atomic and molecular systems of interest have been accessible for precision spectroscopy in the past, since they miss a suitable transition for laser cooling and internal state detection. This restriction can be overcome in trapped ions through quantum logic spectroscopy. Coherent laser manipulation originally developed in the context of quantum information processing with trapped ions allows the combination of the special spectroscopic properties of one ion species (spectroscopy ion) with the excellent control over another species (logic or cooling ion). In my talk I will show that quantum logic spectroscopy enables the development of accurate optical clocks based on aluminium and highly-charged ions as well as precision spectroscopy of broad and non-closed transitions in calcium isotopes. Finally, I present non-destructive internal state detection and spectroscopy of molecular ions using quantum logic. This represents a first step towards extending the exquisite control achieved over selected atomic species to much more complex molecular ions. Applications of quantum logic spectroscopy ranging from the measurement of atomic, molecular and nuclear properties over optical clocks for relativistic geodesy to the search for a variation of fundamental constants will be discussed.

Algebraic Geometry and Representation Theory Seminar

Date:
13
Tuesday
December
2016
Lecture / Seminar
Time: 11:15-12:30
Title: Canonical bases in quantum Schubert cells
Location: Jacob Ziskind Building
Lecturer: Arkady Berenstein
Organizer: Faculty of Mathematics and Computer Science
Abstract: The goal of my talk (based on a recent joint paper with Jacob Greenstein) is to ...The goal of my talk (based on a recent joint paper with Jacob Greenstein) is to provide an elementary construction of the canonical basis B(w) in each quantum Schubert cell U_q(w) and to establish its invariance under Lusztig's symmetries. In particular, I will explain how to directly construct the upper global basis B^up, will show that B(w) is contained in B^up, and that a large part of the latter is preserved by the (modified) Lusztig's symmetries.

Algebraic Geometry and Representation Theory Seminar

Date:
13
Tuesday
December
2016
Lecture / Seminar
Time: 11:15-12:30
Title: Finite-dimensional representations of quantum affine algebras
Location: Jacob Ziskind Building
Lecturer: Jianrong Li
Organizer: Faculty of Mathematics and Computer Science
Abstract: In this talk, I will talk about finite dimensional representations of quantum af ...In this talk, I will talk about finite dimensional representations of quantum affine algebras. The main topics are Chari and Presslay's classification of finite-dimensional simple modules over quantum affine algebras, Frenkel and Reshetikhin's theory of q-characters of finite dimensional modules, Frenkel-Mukhin algorithm to compute q-characters, T-systems, Hernandez-Leclerc's conjecture about the cluster algebra structure on the ring of a subcategory of the category of all finite dimensional representations of a quantum affine algebra. I will also talk about how to obtain a class of simple modules called minimal affinizations of types A, B using mutations (joint work with Bing Duan, Yanfeng Luo, Qianqian Zhang).

Statisical Mechanics Day IX

Date:
13
Tuesday
December
2016
Lecture / Seminar
Time: 09:00-17:00
Location: Edna and K.B. Weissman Building of Physical Sciences
Organizer: Department of Physics of Complex Systems

Paul Dirac – the theorists’ theorist

Date:
08
Thursday
December
2016
Colloquium
Time: 11:15-12:30
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Graham Farmelo
Organizer: Faculty of Physics
Details: 11:00 – coffee, tea, and more
Abstract: Although Paul Dirac was one of the founders of quantum mechanics, his peers alwa ...Although Paul Dirac was one of the founders of quantum mechanics, his peers always perceived him as an outsider, with a unique approach to the subject that was often hard to understand. In this talk, I explain how he came to have such an unusual perspective and why it enabled him to be so productive. In particular, I want to describe the origins of his passion for the idea that mathematical beauty is crucially important to theoreticians who seek the fundamental laws of nature.

AMOS journal club

Date:
06
Tuesday
December
2016
Lecture / Seminar
Time: 13:15-14:30
Location: Edna and K.B. Weissman Building of Physical Sciences
Organizer: Department of Physics of Complex Systems
Details: Noam Matzliah, Ohr Lahad

ISF-NSFC Joint Workshop on Nanosciencer and Nanophotonics

Date:
05
Monday
December
2016
-
06
Tuesday
December
2016
Lecture / Seminar
Time: 09:00 - 18:00
Location: Edna and K.B. Weissman Building of Physical Sciences
Organizer: Department of Physics of Complex Systems

Perovskite Solar Cell Mechanisms Revealed by Light-Soaking Experiments

Date:
23
Wednesday
November
2016
Lecture / Seminar
Time: 11:00-12:00
Location: Perlman Chemical Sciences Building
Lecturer: Prof. Arie Zaban
Organizer: Department of Materials and Interfaces
Details: Starting at 2011, organic-inorganic halide perovskites have emerged as one of the most promising competitors to silicon-based PVs. This is enabled by the unique potential of this family of materials to satisfy the stringent requirements of coupling low energy and low-cost production methods utilizing earth-abundant raw materials with high power conversion efficiency (>21%). Despite a significant research effort which is evident in the constant increase of cell efficiency, the operation mechanism of this PV family is not yet resolved. Aiming at insight to perovskite solar cells mechanisms we performed photoconductivity, Raman, photoluminescence, photovoltage dependence on illumination intensity and open-circuit voltage decay (OCVD) measurements on both free standing perovskite films and full solar cells. All measurements show significant effect of light soaking and return to the original characteristics after dark treatment. In all cases the changes occur over many minutes with slower return (hours) in the dark. The extremely slow changes observed in all measurements cannot be regarded as electronic processes which are much faster but rather as photo-induced structural changes both in the bulk of the perovskite film and at its interface with the electron selective contact. A comprehensive approach to the interpretation of the five measuring techniques, three different perovskite materials and both free standing films and operating cells, provide new insight to the operation mechanism of perovskite solar cells

Chemical Physics Department Guest Seminar

Date:
22
Tuesday
November
2016
Lecture / Seminar
Time: 11:30
Title: Probing High Temperature Chemistry with Spectroscopy
Location: Perlman Chemical Sciences Building
Lecturer: Dr Joshua Baraban
Organizer: Department of Chemical and Biological Physics
Abstract: Processes and species encountered at high temperatures are important in a wide r ...Processes and species encountered at high temperatures are important in a wide range of scientific and applied fields including combustion, atmospheric chemistry, and molecular astronomy. Understanding these reactions and molecules, however, is difficult due to the complex nature of the chemistry that occurs in extreme environments. I will discuss novel spectroscopic tools, both conceptual and experimental, for attacking molecular questions in high temperature chemistry. These capabilities not only enable the complete mapping of kinetic reaction networks, but also open new windows onto high temperature behavior by providing an additional dimension of quantum state specific data.

SPACETIME RECONSTRUCTION IN APPLIED HOLOGRAPHY

Date:
22
Tuesday
November
2016
Lecture / Seminar
Time: 10:30
Lecturer: CINDY KEELER
Organizer: Department of Particle Physics and Astrophysics
Details: 10:20 Gathering and coffee
Abstract: Abstract: After a brief review of holographic techniques derived from the AdS-CF ...Abstract: After a brief review of holographic techniques derived from the AdS-CFT correspondence, we specialize to a class of spacetimes proposed as duals to non-relativistic systems. We highlight classical and quantum features of these "Lifshitz spacetimes" which limit the reconstructability of bulk spacetime information from boundary data. We additionally discuss the fate of various spacetime reconstruction procedures in Lifshitz spacetimes. We close by examining the limitations placed on entropy-based spacetime reconstruction due to holographic screens

Guided design of new Quantum materials

Date:
10
Thursday
November
2016
Colloquium
Time: 11:15-12:30
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Leslie Schoop
Organizer: Faculty of Physics
Details: 11:00 – coffee, tea, and more
Abstract: The realization of new quantum effects in materials strongly depends on the disc ...The realization of new quantum effects in materials strongly depends on the discovery of compounds that can exhibit these effects. For example, although first predictions were made in the 70s, the field of topological insulators only really grew after topological materials were discovered that could be studied. In order to create new materials that exhibit new and exotic physical properties, knowledge about the periodic table and chemical concepts is extremely useful. In this talk, I will introduce some basic chemical concepts and show how they can be used as a guide to develop new superconductors, 3D Dirac semimetals and two-dimensional magnets

A ONE-DIMENSIONAL THEORY FOR HIGGS BRANCH OPERATORS

Date:
08
Tuesday
November
2016
Lecture / Seminar
Time: 12:00-13:30
Lecturer: Ran Yacoby
Organizer: Department of Particle Physics and Astrophysics
Abstract: I will show how supersymmetric localization can be used to calculate correlatio ...I will show how supersymmetric localization can be used to calculate correlation functions of half-BPS local operators in 3d N=4 superconformal field theories whose Lagrangian descriptions consist of vectormultiplets coupled to hypermultiplets. The operators primarily studied are certain twisted linear combinations of Higgs branch operators that can be inserted anywhere along a given line. These operators are constructed from the hypermultiplet scalars. They form a 1d non-commutative operator algebra with topological correlation functions. The 2- and 3-point functions of Higgs branch operators in the full 3d N=4 theory can be simply inferred from the 1d topological algebra. After conformally mapping the 3d superconformal field theory from flat space to a round three-sphere, supersymmetric localization is performed using a supercharge that does not belong to any 3d N=2 subalgebra of the N=4 algebra. The result is a simple model that can be used to calculate correlation functions in the 1d topological algebra mentioned above. This model is a 1d Gaussian theory coupled to a matrix model, and it can be viewed as a gauge-fixed version of a topological gauged quantum mechanics. These results generalize to non-conformal theories on S3 that contain real mass and Fayet-Iliopolous parameters. I will also provide partial results for the 1d topological algebra associated with the Coulomb branch, where correlators of operators built from the vectormultiplet scalars will be considered.

A DUALITY WEB IN 2 + 1 DIMENSIONS AND THE UNITY OF PHYSICS

Date:
08
Tuesday
November
2016
Lecture / Seminar
Time: 10:30-12:00
Lecturer: Nati Seiberg
Organizer: Department of Particle Physics and Astrophysics
Abstract: A combination of ideas originating from Condensed Matter physics, Supersymmetric ...A combination of ideas originating from Condensed Matter physics, Supersymmetric Field Theory, and AdS/CFT has led to a detailed web of conjectured dualities. These relate the long distance behavior of different short distance theories. These dualities clarify a large number of confusing and controversial issues in Condensed Matter physics and in the study of 2+1 dimensional quantum field theory.

Pre-SAAC Symposium on Astrophysics and Astroparticles

Date:
06
Sunday
November
2016
Lecture / Seminar
Time: 10:00-16:00
Location: Edna and K.B. Weissman Building of Physical Sciences
Organizer: Faculty of Physics

Astrophysics in real time: observing stars as they explode

Date:
03
Thursday
November
2016
Colloquium
Time: 11:15-12:00
Title: The fifty first Giulio Racah Memorial Lecture
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Prof. Avishay Gal Yam
Organizer: Faculty of Physics
Details: 11:00 Coffee, tea and more

Vision and Robotics Seminar

Date:
26
Monday
September
2016
Lecture / Seminar
Time: 14:00-15:30
Title: From the Optics Lab to Computer Vision
Location: Jacob Ziskind Building
Lecturer: Achuta Kadambi
Organizer: Faculty of Mathematics and Computer Science

3rd Solar Fuels I-CORE Workshop

Date:
12
Monday
September
2016
-
15
Thursday
September
2016
Conference
Time: 08:00

From Quantum Chaos to Graphs and Spectral Patterns

Date:
11
Sunday
September
2016
-
15
Thursday
September
2016
Conference
Time: 08:00
Location: David Lopatie Conference Centre

Observation of quantum Hawking radiation and its entanglement in an analogue black hole

Date:
08
Thursday
September
2016
Colloquium
Time: 11:15-12:30
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Jeff Steinhauer
Organizer: Faculty of Physics
Details: 11:00 – coffee, tea, and more
Abstract: We observe spontaneous Hawking radiation, stimulated by quantum vacuum fluctuati ...We observe spontaneous Hawking radiation, stimulated by quantum vacuum fluctuations, emanating from an analogue black hole in an atomic Bose-Einstein condensate. The Hawking radiation is observed via the correlations between the Hawking radiation exiting the black hole and the partner particles falling into the black hole. The quantum nature of the Hawking radiation is observed through entanglement, by comparing the Fourier transform of the corre-lations to a measurement of the population. This comparison shows that the experiment is well within the quantum regime, since the measured Hawking temperature determined from the population distribution is far below the upper limit for quantum entanglement. A broad energy spectrum of entangled Hawking pairs are observed. Maximal entanglement is ob-served for the high energy part of the Hawking spectrum, while the lowest energies are not entangled. Thermal behavior is seen at very low energies where the finite extent of the corre-lation function implies frequency dependence. Thermal behavior is also seen at high energies through the agreement of the correlation spectrum with the appropriate function of the Planck distribution. Further insight is obtained by a preliminary experiment in which the horizon is caused to oscillate at a fixed frequency, which stimulates waves travelling into and out of the black hole. The rate of particle production by the oscillating horizon is consistent with the measured Hawking temperature. Furthermore, the observed ratio of the phase velocities of the Hawking and partner particles are consistent with this preliminary ex-periment, as is the width of the Hawking/partner correlation feature. Additional confirmation of the results is obtained through a numerical simulation, which demonstrates that the Hawk-ing radiation occurs in an approximately stationary background. It also confirms the width of the Hawking/partner correlation feature. The measurement reported here verifies Hawking’s calculation, which is viewed as a milestone in the quest for quantum gravity. The observation of Hawking radiation and its entanglement verifies important elements in the discussion of information loss in a real black hole.

Current fluctuations in boundary driven systems : Universality, dynamical phase transitions and quantum transport

Date:
20
Monday
June
2016
Lecture / Seminar
Time: 14:15
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Ohad Shpielberg
Organizer: Department of Physics of Complex Systems
Details: The recently formulated macroscopic fluctuation theory is a successful description of out of equilibrium diffusive systems. I will focus on current fluctuations of boundary driven systems within the macroscopic theory description, and discuss the relevance of the additivity principle to derive the large deviation function associated with the current fluctuations. Three results will be shown (1 Current fluctuations in boundary driven systems are universal (2A criterion for the validity of the additivity principle and application to dynamical phase transitions. 3) Relevance of the macroscopic fluctuation theory to transport of disordered quantum systems.

The Chaim Leib Pekeris Memorial Lecture

Date:
14
Tuesday
June
2016
Lecture / Seminar
Time: 11:30-13:00
Title: The Quantum Computer Puzzle
Lecturer: Gil Kalai
Organizer: Faculty of Mathematics and Computer Science

Regime shifts in spatially extended dryland ecosystems

Date:
06
Monday
June
2016
Lecture / Seminar
Time: 14:15
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Yuval Zelnik
Organizer: Department of Physics of Complex Systems
Abstract: Regime shifts in ecosystems are typically understood to be abrupt global transit ...Regime shifts in ecosystems are typically understood to be abrupt global transitions from one stable state to an alternative stable state, induced by slow environmental changes or global disturbances. This is especially relevant to drylands, where desertification is a major concern. However, spatially extended ecosystems, and dryland vegetation systems in particular, often exhibit patterned states, which allow for more complex dynamics to take place. Periodic patterns can have many different wavelengths, implying different length-scales of patchy vegetation. Further, a bistability of a patterned state and a uniform state can lead to a multitude of stable hybrid states, with small domains of one state embedded in the other state. The response of the system to local disturbances or change in global parameters in these systems can lead to gradual regime shifts, involving the expansion of alternative-state domains by front propagation, rather than a global collapse. Moreover, a regime of periodic perturbations can give rise to step-like gradual shifts with extended pauses at these states. The implications of different forms of patterned states on the dynamics of the system will be discussed, with three points in mind: The question of desertification as a front propagation process, the effect of local disturbances on the system, and a specific case study on the dynamics of fairy circles in Namibia as a concrete example.

“Perovskite Solar Cells from Fundamental Issues to Advanced Concepts

Date:
06
Monday
June
2016
Lecture / Seminar
Time: 14:00-15:00
Location: Perlman Chemical Sciences Building
Lecturer: Dr. Ivan Mora Sera
Organizer: Department of Materials and Interfaces
Details: Halide Perovskite are probably the current hottest materials for photovoltaics. Certified photoconversion efficiencies as high as 22.1% has been reported. In addition, can be prepared from solution methods at low temperature, and consequently they can be fabricated without large and expensive facilities, and can be easily combined with other materials. However despites the unprecedentedly fast increase of the reported efficiencies, especially in the last four years, the working mechanisms of this kind of devices are not completely understood. As example the cells with the highest efficiency reported presents a thin TiO2 scaffold with a thicker perovskite capping layer, but it is not completely clear why this configuration provides such high efficiency with suppression of hysteresis effect. Transport, recombination, injection at the contacts or J-V curve hysteresis are strongly dependent on the cell configuration, as the use of scaffold, the perovskite and contact materials and also on the growth conditions. In this talk, I analyze the effect of different electron selective contacts, in the solar cell performance. In addition, I show the effect of different scaffold configuration in the properties of the device by a systematic optoelectronic characterization. Finally, I analyze the fact that to obtain efficiencies as the ones reported for Perovskite Solar Cells (PSCs) it is needed a low non-radiative recombination, allowing the development of light emitting systems. In addition, the interaction among materials of different nature can produce interesting synergies that might be beneficial, not simply by improving a feature, but also giving rise to new properties or phenomena that do not exist for the single materials. The interaction between hybrid lead halide perovskite (CH3NH3PbI3) and quantum dots (core/shell PbS/CdS) is presented.1 Interaction between QDs and perovskite has enormous potentialities.1-3 We report for the first time the observation of exciplex state electroluminescence from the combination of both materials. The presence of the exciplex state of perovskite and QDs opens up a broad range of possibilities with important implications in tunable LEDs but also in the preparation of intermediate band gap photovoltaic devices with the potentiality of surpassing the Shockley-Queisser (SQ) limit.

Flatland II: Not only opposites attract

Date:
02
Thursday
June
2016
Colloquium
Time: 11:15-12:30
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Jurgen Smet
Organizer: Faculty of Physics
Details: 11:00 – coffee, tea, and more
Abstract: The dominant interaction that pops into our mind when considering like charges c ...The dominant interaction that pops into our mind when considering like charges constraint to move in a plane is no doubt the repulsive Coulomb interaction. It produces the celebrated fractional quantum Hall effect that continues to fascinate and whose appearance frequently acts as a Litmus test for the quality of emerging materials. However, every so often the ubiqui-tous Coulomb repulsion has to give way to physics that apparently involves local attractive interactions among our like charges instead. Electron pairing, mediated by electron phonon interactions and leading to superconductivity, would be an obvious example outside of the context of flatland. However, the mechanism mediating or delivering a local attractive interaction is commonly not that obvious. In this presentation instances of such local attraction physics in flatland without phonon involvement will be covered. We will address various techniques beyond simple magneto-transport that help us to unveil these local attractive interactions and its consequences. This physics is very fragile and its study has been the exclusive privilege of the very mature GaAs community so far. We will highlight that this is no longer true.

Chemical Physics Department Guest Seminar

Date:
31
Tuesday
May
2016
Lecture / Seminar
Time: 10:00
Title: Optical control of electronic and nuclear states: Toward quantum computing in self-assembled dots
Location: Gerhard M.J. Schmidt Lecture Hall
Lecturer: Prof. Duncan Steel
Organizer: Department of Chemical and Biological Physics

Geometric Heat Engines Without Power-Efficiency Tradeoff

Date:
30
Monday
May
2016
Lecture / Seminar
Time: 14:15
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: OREN RAZ
Organizer: Department of Physics of Complex Systems
Abstract: Thermodynamics places a limit on the efficiency of heat engines, but not on thei ...Thermodynamics places a limit on the efficiency of heat engines, but not on their output power or on how the power and efficiency change with the engine’s cycle time. In the talk I will present a geometrical description of the power and efficiency as a function of the cycle time, applicable to an important class of heat engine models. This geometrical description is used to design engine protocols that attain both the maximal power and maximal efficiency at the fast driving limit. Furthermore, using this method, we also prove that no protocol can exactly attain the Carnot efficiency at nonzero power. Ref: PRL 116, 160601 (2016)

Cosmological Probes of Fundamental Physics

Date:
29
Sunday
May
2016
-
10
Friday
June
2016
Conference
Time: 00:00
Location: Edna and K.B. Weissman Building of Physical Sciences

Cold atoms, free fermions and the Kardar-Parisi-Zhang equation

Date:
23
Monday
May
2016
Lecture / Seminar
Time: 14:15
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: SATYA MAJUMDAR
Organizer: Department of Physics of Complex Systems
Abstract: There have been spectacular progress in cold atoms experiments in recent years. ...There have been spectacular progress in cold atoms experiments in recent years. As a simple example of a system of noninteracting cold atoms, I'll discuss the case of N free fermions trapped in a harmonic well. We will see that even without interactions, this is an interesting many-body system with nontrivial quantum fluctuations arising purely from the Pauli exclusion principle. In 1d and at T=0, the quantum fluctuations of the positions of the fermions can be exactly mapped to the distribution of eigenvalues of a Gaussian Hermitian random matrix. A lot of nice exact results for the fermions can be extracted using this correspondence. In particular, this connection to random matrix theory predicts exact results at the edges of the fermion density profile, where fluctuations dominate and traditional theories of quantum many-body systems do not work. One example of such exact results at the edges is that the position of the rightmost fermion in 1-d, at T=0, is described by the celebrated Tracy-Widom distribution for the top eigenvalue of a random matrix. I'll then discuss how these results can be generalized to finite temperature. Remarkably, at finite T, the position of the rightmost fermion is closely related to distribution as the height at finite time of the (1+1)-dimensional interfaces described by the continuum Kardar-Parisi-Zhang equation. Interesting results at finite temperature can be derived by exploiting this connection as well. If time permits, I'll also discuss the generalizations to higher dimensions.

Theoretical applications of topological insulators: a new window into quantum matter

Date:
19
Thursday
May
2016
Colloquium
Time: 11:15-12:30
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Senthil Todadri
Organizer: Faculty of Physics
Details: 11:00 – coffee, tea, and more
Abstract: The discovery of topological band insulators is one of the most exciting develop ...The discovery of topological band insulators is one of the most exciting developments in condensed matter physics in the last decade. In this talk I will describe how insights from the study of the relatively simple topological insulators are revolutionizing our theoretical understanding of more complex quantum many body systems. The latter include states of strongly interacting quantum matter which have been at the forefront of research in the last 3 decades. Specific examples include quantum spin liquid states of insulating magnets, and the theory of composite fermions in quantum Hall systems. The theory of topological insulators unifies these seemingly diverse problems, and provides a new window through which to view them leading to many new and fundamental results.

The Quantum Way of Doing Computations

Date:
05
Thursday
May
2016
Colloquium
Time: 11:15-12:30
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Rainer Blatt
Organizer: Faculty of Physics
Details: 11:00 – coffee, tea, and more
Abstract: Since the mid-nineties of the 20th century it became apparent that one of the ce ...Since the mid-nineties of the 20th century it became apparent that one of the centuries’ most important technological inventions, computers in general and many of their applications could possibly be further enormously enhanced by using operations based on quantum physics. This is timely since the classical roadmaps for the development of computational devices, commonly known as Moore’s law, will cease to be applicable within the next decade due to the ever smaller sizes of the electronic components that soon will enter the quantum physics realm. Computations, whether they happen in our heads or with any computational device, always rely on real physical processes, which are data input, data representation in a memory, data manipulation using algorithms and finally, the data output. Building a quantum computer then requires the implementation of quantum bits (qubits) as storage sites for quantum information, quantum registers and quantum gates for data handling and processing and the development of quantum algorithms. In this talk, the basic functional principle of a quantum computer will be reviewed. It will be shown how strings of trapped ions can be used to build a quantum information processor and how basic computations can be performed using quantum techniques. In particular, the quan-tum way of doing computations will be illustrated by analog and digital quantum simulations, which reach from the simulation of quantum many-body spin systems over open quantum systems to the quantum simulation of a lattice gauge theory.

Electromechanics: A new quantum technology

Date:
21
Thursday
April
2016
Colloquium
Time: 00:00
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Konrad Lenhert
Organizer: Faculty of Physics
Details: 11:00 – coffee, tea, and more
Abstract: Devices that combined electricity with moving parts were crucial to the very ear ...Devices that combined electricity with moving parts were crucial to the very earliest electronic communications. Today, electromechanical structures are ubiquitous yet under-appreciated signal processing elements. Because the speed of sound is so slow compared to the speed of light, they are used to create compact filter and clock elements. Moreover they convert force and acceleration signals into more easily processed electrical signals. Can these humble, apparently classical, objects exhibit genuinely quantum behavior? Indeed—by strongly coupling the vibrations of a micromechanical oscillator to microwave frequency electrical signals, a mechanical oscillator can inherit a quantum state from an electrical signal. This recent and exciting result heralds the development of a quantum processors or quantum enhanced sensors that exploit the unique properties of mechanical systems. Furthermore, quantum electromechanics provides a powerful and versatile way to bring ever larger, more tangible objects into non-classical regimes.

Braginsky Center for the Interface between the Sciences and the Humanities

Date:
20
Wednesday
April
2016
Lecture / Seminar
Time: 15:30
Title: IF YOU WANT TO SEE, TURN YOUR HEAD
Location: Dolfi and Lola Ebner Auditorium
Lecturer: Professor Mitchell J. Feigenbaum
Organizer: Department of Chemical and Biological Physics
Abstract: We present a discussion of aspects of vision determined by the physics underlyin ...We present a discussion of aspects of vision determined by the physics underlying our ability to perceive “non-objects”. These are astigmatic objects, including some classical anamorphisms found in curio cabinets of kings; our view of things below the surface of water, and reciprocally, a fish’s view of what is above that surface. These non-objects provide some deep insights into our binocular vision and notions of perspective. Considering the optics of the eyes that see these things, a curiosity of evolution arises in the much finer design of the fish’s eye than our own, its considerably newer successor.

Nuclear physics from (lattice) quantum chromodynamics

Date:
18
Monday
April
2016
Lecture / Seminar
Time: 14:30-15:30
Lecturer: Johannes Kirscher
Organizer: Department of Particle Physics and Astrophysics
Details: 14:15 - 14:30 Refreshments 15:30 - 16:00 Coffee Break
Abstract: I will present recent progress in the fundamental derivation of the theory of nu ...I will present recent progress in the fundamental derivation of the theory of nuclei, beginning with the recent progress in obtaining few-nucleon amplitudes directly from QCD via the lattice method. The theoretical framework devised for this data will be introduced with a brief motivation for the effective-field-theory formalism. Result obtained within this approach for the three and four-nucleon system and an outlook on the future of the program will conclude the talk.

Mesoscopic Thermodynamics

Date:
14
Thursday
April
2016
Colloquium
Time: 11:15-12:30
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Klaus Ensslin
Organizer: Faculty of Physics
Details: 11:00 – coffee, tea, and more
Abstract: Transport through quantum system is usually investigated in thermodynamic equili ...Transport through quantum system is usually investigated in thermodynamic equilibrium. As systems shrink in size fluctuations get ever more important and may even dominate the electronic properties of quantum devices. A charge detector capacitively coupled to a semiconductor quantum dot can be used to measure the passing of individual electrons through the systems, i.e. to measure the current on the level of individual charge carriers. The tunneling barriers as well as the dot occupation can be tuned on time scales faster than typical relaxation times in order to measure level degeneracies, energy dependent tunneling rates and decay times. For situations far from equilibrium the Jarzynski relation gives a clear prediction how out-of-equilibrium properties can be related to equilibrium properties, such as the free energy of a system. These relations can be probed experimentally using time-dependent electron transport through semiconductor quantum dots. As an introduction to clean semiconductor systems I will review recent results on Fermionic cavities.

Clore Seminar on Soft and Biological Physics

Date:
27
Sunday
March
2016
Lecture / Seminar
Time: 13:00
Title: The Geometry and Mechanics of Growing Elastic Sheets
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Prof. Eran Sharon
Organizer: Department of Physics of Complex Systems
Abstract: Many natural structures are made of soft tissue that undergoes active growth. No ...Many natural structures are made of soft tissue that undergoes active growth. Non uniform growth of thin sheets can lead to the formation of elaborate three-dimensional configurations and to induce non trivial shape transformations. In particular, complicated configurations appear in thin sheets when growth leads to geometrical frustration. I will present examples of different types of systems and discus different types of self-shaping principles, together with the theoretical framework of incompatible elasticity which is used to study such systems. Experimental methods for the construction of “programmed” responsive sheets will be reviewed and the connection of the topic to shape selection in chemical and biological systems, as well as to design and art, will be presented.

Chemical Physics Department Guest Seminar

Date:
23
Wednesday
March
2016
Lecture / Seminar
Time: 15:00
Title: Quantum computers - is the future here?
Location: Gerhard M.J. Schmidt Lecture Hall
Lecturer: Prof. Tal Mor
Organizer: Department of Chemical and Biological Physics
Abstract: About thirty years ago Richard Feynman and David Deutsch came up with the quan ... About thirty years ago Richard Feynman and David Deutsch came up with the quantum computer. A decade later Peter Shor had shown the incredible power of quantum computers: He showed their ability to factorize large numbers, an ability whose technological consequences for the world of internet encryption and banking can be devastating. In the last four years the Wolf Prize and the Nobel Prize were given to researchers promoting quantum computing technologies, and the (only existing) startup has sold "quantum simulators" to Lockheed Martin, as well as to Google and NASA. Is the future here? Or will we have to wait for it for a few more decades? The answer depends upon whom you ask. In this presentation I will try to clearly present the current situation of this field. I will also present the important notion of semi-quantum computing also called sub-universal quantum computing.

Fluctuations in inhomogeneous systems: From biopolymers through glasses to Casimir-like forces

Date:
21
Monday
March
2016
Lecture / Seminar
Time: 14:15
Location: Dannie N. Heineman Laboratory
Lecturer: Yohai Bar Sinai, WIS
Organizer: Department of Physics of Complex Systems
Details: Both thermal fluctuations and material inhomogeneity/disorder play a major role in many branches of science. This talk will focus on various aspects of the interplay between the two. First, we consider the spatial distribution of thermal fluctuational energy and derive universal bounds for internal-stress-free systems. In addition, we show that in 1D systems the thermal energy is equally partitioned even among coupled degrees of freedom. Applications to severing of actin filaments and protein unfolding are discussed. Then, we consider fluctuations in residually-stressed systems and their coupling to non-linearities. In the context of glassy systems, we show that thermal energy is spatially localized and suggest that it might serve as a useful structural diagnostic tool, e.g. for identifying glassy lengthscales and precursors to plastic events under driving forces. Lastly, we consider the continuum approach (Statistical Field Theory) to analyzing fluctuations in inhomogeneous systems, and demonstrate fundamental discrepancies between the continuum and the discrete theories in explicit 1D calculations of some, but not all, fluctuation-induced (Casimir-like) forces. References: Bar-Sinai & Bouchbinder. PRE 91 060103(R), 2015 Bar-Sinai & Bouchbinder arXiv 1601.01425

Fluctuations in inhomogeneous systems: From biopolymers through glasses to Casimir-like forces

Date:
21
Monday
March
2016
Lecture / Seminar
Time: 14:15
Location: Dannie N. Heineman Laboratory
Lecturer: Yohai Bar Sinai, WIS
Organizer: Department of Physics of Complex Systems
Details: Both thermal fluctuations and material inhomogeneity/disorder play a major role in many branches of science. This talk will focus on various aspects of the interplay between the two. First, we consider the spatial distribution of thermal fluctuational energy and derive universal bounds for internal-stress-free systems. In addition, we show that in 1D systems the thermal energy is equally partitioned even among coupled degrees of freedom. Applications to severing of actin filaments and protein unfolding are discussed. Then, we consider fluctuations in residually-stressed systems and their coupling to non-linearities. In the context of glassy systems, we show that thermal energy is spatially localized and suggest that it might serve as a useful structural diagnostic tool, e.g. for identifying glassy lengthscales and precursors to plastic events under driving forces. Lastly, we consider the continuum approach (Statistical Field Theory) to analyzing fluctuations in inhomogeneous systems, and demonstrate fundamental discrepancies between the continuum and the discrete theories in explicit 1D calculations of some, but not all, fluctuation-induced (Casimir-like) forces. References: Bar-Sinai & Bouchbinder. PRE 91 060103(R), 2015 Bar-Sinai & Bouchbinder arXiv 1601.01425

Hydrodynamics of a small swimming robot

Date:
14
Monday
March
2016
Lecture / Seminar
Time: 14:15
Location: Dannie N. Heineman Laboratory
Lecturer: Aryesh Mukherjee, WIS
Organizer: Department of Physics of Complex Systems
Abstract: Fish and insects live in fluid environments and use numerous techniques to survi ...Fish and insects live in fluid environments and use numerous techniques to survive in a hostile environment. Small insects beat their wings many times a second, and can couple fluid vortices to the elasticity of their wings to generate optimal flight modes within short time scales. Motivated by such observations, we borrowed such passive techniques to design a small swimming robot, equipped with a flexible tail. The robot is capable of swimming at high speeds, but more importantly its thrust is maximized at a frequency where the elasticity of the tail couples strongly with the fluid environment, beyond just added mass effects. In this talk we will discuss the physical principles that govern the kinematics of this robotic device.

Hydrodynamics of a small swimming robot

Date:
14
Monday
March
2016
Lecture / Seminar
Time: 14:15
Location: Dannie N. Heineman Laboratory
Lecturer: Aryesh Mukherjee, WIS
Organizer: Department of Physics of Complex Systems
Abstract: Fish and insects live in fluid environments and use numerous techniques to survi ...Fish and insects live in fluid environments and use numerous techniques to survive in a hostile environment. Small insects beat their wings many times a second, and can couple fluid vortices to the elasticity of their wings to generate optimal flight modes within short time scales. Motivated by such observations, we borrowed such passive techniques to design a small swimming robot, equipped with a flexible tail. The robot is capable of swimming at high speeds, but more importantly its thrust is maximized at a frequency where the elasticity of the tail couples strongly with the fluid environment, beyond just added mass effects. In this talk we will discuss the physical principles that govern the kinematics of this robotic device.

Chemical Physics Department Guest Seminar

Date:
10
Thursday
March
2016
Lecture / Seminar
Time: 15:30
Title: Nonlinear optics of plasmonic nanostructures
Location: Perlman Chemical Sciences Building
Lecturer: Dr. Radoslaw Kolkowski
Organizer: Department of Chemical and Biological Physics

The molecular universe

Date:
10
Thursday
March
2016
Colloquium
Time: 11:15-12:30
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Francoise Combes
Organizer: Faculty of Physics
Details: 11:00 – coffee, tea, and more
Abstract: I will review some recent results about the molecular content of galaxies across ...I will review some recent results about the molecular content of galaxies across the Hubble time. Molecular gas is essential to determine the star formation efficiency in galaxies, and understand their evolution. Large progress has been made on galaxy at moderate and high redshifts, allowing to interprete the star formation history of the universe: in massive galaxies, the gas fraction was ~5 times higher in the past, and galaxy disks were more unstable and more turbulent. Molecular outflows are now frequently discovered in AGN-hosts, able to quench star formation. AGN feedback is required to reproduce the observed galaxy mass function. ALMA observations will allow the study of main sequence galaxies at high z with higher spatial resolution and sensitivity.

Creating, Controlling, and Diagnosing High Energy Density Matter with the National Ignition Facility

Date:
02
Wednesday
March
2016
Colloquium
Time: 11:00-12:00
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Mark Herrmann
Organizer: Faculty of Physics
Details: 10:45 – coffee, tea, and more
Abstract: The National Ignition Facility (NIF), at Lawrence Livermore National Laboratory, ...The National Ignition Facility (NIF), at Lawrence Livermore National Laboratory, is the world’s most energetic laser and it has been in routine operation since 2009. NIF consists of 192 beams that can deliver over 1.8 MJ of ultraviolet energy in a few nanoseconds. These beams deliver >400 TW of power to targets much smaller than a cm3. The deposition of this energy in a small volume creates extreme radiation environments and large pressures in materials. These very large pressures and radiation environments can be used to create matter at high energy densities (usually defined by an energy density exceeding about 0.1 MJ/cm3 or pres-sures greater than 106 times atmospheric pressure). NIF is used to perform state of the art ex-periments in the field of high energy density science, enabling us to address many fundamen-tal questions on the behavior of matter at high pressures. Particular areas of focus include the study of materials that make up planetary interiors and exploring astrophysics related phe-nomena in the laboratory. A primary goal of the NIF is to obtain thermonuclear fusion ignition in the laboratory by using x-rays to compress fusion fuel to extreme conditions. In this talk, I will provide an overview of the National Ignition Facility and some of the amazing technology that enables it. I will discuss recent progress in high energy density science and inertial con-finement fusion, and talk about the challenges and opportunities for future research.

High Energy Density Materials at Sandia: Investigations in Planetary Science

Date:
01
Tuesday
March
2016
Lecture / Seminar
Time: 11:15
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Dawn Flicker
Organizer: Department of Particle Physics and Astrophysics
Details: 11:00 – Light refreshments
Abstract: The structure and evolution of planets is determined by material behavior at hig ...The structure and evolution of planets is determined by material behavior at high pressure. Such high pressures can only be achieved at High Energy Density (HED) facilities like Sandia’s Z machine and high-power laser facilities. Z stores 22MJ of energy that is released in pulses of up to 25MA peak current with 200-1000ns rise times. The large currents generate strong magnetic fields that can be used to create high pressures in dynamic material experiments. This capability enables evaluation of material equation-of-state and other properties in extreme conditions. I will present three examples using experimental results from the Z machine to answer long-standing questions in planetary science. First, solar system evolution models have been unable to consistently account for observations of Jupiter and Saturn. Recent Z observations of a first-order liquid-liquid insulator to metal transition in hydrogen may shed light on this discrepancy. Second, measurements of iron vaporization may address troubling differences between models of the Earth’s moon forming event and observations of the Earth and moon’s compositions. Finally, precise measurements of high-pressure water were used to validate DFT models which in turn informed planetary structure models suggesting an explanation of the multi-polar magnetic fields of Neptune and Uranus. The Z Fundamental Science Program (ZFSP), which enables the academic community to take advantage of the facility enabling much of this work, will be described. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000.

Resilience of Multidimensional Complex Systems

Date:
29
Monday
February
2016
Lecture / Seminar
Time: 14:15
Location: Dannie N. Heineman Laboratory
Lecturer: Baruch Barzel
Organizer: Department of Physics of Complex Systems
Abstract: Resilience is a system's ability to cope with change, or to bounce back after st ...Resilience is a system's ability to cope with change, or to bounce back after stress. The loss of resilience in a natural system occurs when the stress exceeds a certain threshold, beyond which the system loses its ability to bounce back and retain proper functionality. For instance, when the loss of trees in a forest (deforestation) crosses a tipping point and the forest turns barren, or when the load on the electrical power grid becomes too high and a massive power failure emerges. The challenge is that most complex systems are multidimensional, disordered and described by nonlinear dynamics - characteristics that firmly avoid analytical treatment. We address this challenge by showing how to map a complex system into an effective one dimensional equation, exposing the universal patterns of resilience exhibited by diverse systems, from ecological to technological networks. Along the way we will understand why systems lose resilience all of a sudden, learn how to predict such resilience loss and show how to fortify a system to become more resilient. J. Gao, B. Barzel, A-L Barabasi, Nature 530, 307 (2016).

SCATTERING THEORY IN TERMS OF CURRENTS AT INFINITY, AND ITS RELATION TO HOLOGRAPHIC SPACETIME”

Date:
23
Tuesday
February
2016
Lecture / Seminar
Time: 12:00-13:30
Lecturer: TOM BANKS
Organizer: Department of Particle Physics and Astrophysics
Abstract: : The Wheeler DeWitt equation is the statement that theories of gravity are topo ...: The Wheeler DeWitt equation is the statement that theories of gravity are topological in the bulk and only have boundary DOF. This fits with the Covariant entropy conjecture, which associates an areas worth of DOF to the boundary of a causal diamond. For nested diamonds it implies that the algebra of operators on the smaller one be a proper subalgebra of that on the larger one. Jacobson showed, conversely, that the area law implies Einstein's equations (except for the c.c., which Banks and Fischler argued was an asymptotic boundary condition). In Minkowski space, the maximal causal diamond is Penrose's conformal boundary. Traditionally we deal with this by introducing an S matrix, but this only works in perturbation theory because of the inevitable existence of states with arbitrary numbers of arbitrarily soft gravitons (even when there are no IR divergences). Instead we introduce an algebra of densities describing the flow of quantum numbers out to null infinity. The simplest of these are the commuting BMS local translations, which one can diagonalize. The joint spectrum of the past and future BMS generators defines a null cone, and all other currents may be thought of as generalized functions on this cone. The algebra must include helicity raising operators and the simplest way to introduce them (perhaps the only consistent way) is to write a generalization of the Awada Gibbons Shaw supersymmetric BMS algebra. One must define Sterman Weinberg jet representations of this algebra, which reveal that particle energy is related to constraints on the density degrees of freedom. Retreating from infinity to a finite causal diamond, the current algebra is cutoff by cutting off the spectrum of the Dirac operator on the holographic screen - a UV/IR correspondence reminiscent of that in AdS/CFT.

“DUALITY AND THE ENTANGLEMENT WEDGE IN ADS/CFT”

Date:
23
Tuesday
February
2016
Lecture / Seminar
Time: 10:30-12:00
Lecturer: DANIEL HARLOW
Organizer: Department of Particle Physics and Astrophysics
Details: 10:20 Gathering and coffee
Abstract: Evidence has gradually accumulated that in AdS/CFT, any spatial subregion of the ...Evidence has gradually accumulated that in AdS/CFT, any spatial subregion of the CFT has complete quantum information about some subregion of the bulk spacetime. Exactly which bulk subregion this is has been a matter of some debate, which has focused on the "causal wedge" and the "entanglement wedge" as the primary candidates. In this talk I will present a few theorems which together essentially resolve this debate in favor of the entanglement wedge. The argument combines recent work on quantum corrections to the Ryu-Takayanagi formula with the idea that the correspondence can be interpreted as a quantum error-correcting code.

Exploring Quantum Simulations with Superconducting Cir-cuits

Date:
18
Thursday
February
2016
Colloquium
Time: 11:15-12:30
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Andreas Wallraf
Organizer: Faculty of Physics
Details: 11:00 – coffee, tea, and more
Abstract: The high level of control achievable over quantized degrees of freedom have turn ...The high level of control achievable over quantized degrees of freedom have turned super-conducting circuits into one of the prime physical architectures for quantum computing and simulation. While conventional approaches mostly rely on unitary time evolution more recently open-system dynamics are considered for quantum information processing and simulations as well. In this talk, I will first give an introduction to superconducting quantum circuits. Then I will discuss a set of experiments in which we simulated the physics of interacting spins using a digital approach [1]. In a second set of experiments [2] we made use of an open cavity quantum electrodynamics (QED) system with tunable interactions to simulate the ground state of an interacting Bose gas confined in one dimension [3,4]. These experiments rely on our ability to efficiently measure higher order photon correlations of propagating microwave fields. To facilitate these measurements we developed a quantum limited amplifier achieving phase-preserving amplification at large bandwidth and high dynamic range [5]. Our results demonstrate an alternative path towards simulating complex quantum many-body physics based on the controlled generation and detection of nonclassical radiation in open quantum systems. [1] Y. Salathe et al., Phys. Rev. X 5, 021027 (2015). [2] C. Eichler et al., Phys. Rev. X 5, 041044 (2015). [3] S. Barrett et al., Phys. Rev. Lett. 110, 090501 (2013). [4] F. Verstraete and J. I. Cirac, Phys. Rev. Lett. 104, 190405 (2010). [5] C. Eichler et al., Phys. Rev. Lett. 113, 110502 (2014).

Mechanical Yield to Plastic Flow in Amorphous Materials

Date:
15
Monday
February
2016
Lecture / Seminar
Time: 14:15
Lecturer: Itamar Procaccia,WIS
Organizer: Department of Physics of Complex Systems
Abstract: Materials that exhibit a "yield" phenomenon response elastically to small strain ...Materials that exhibit a "yield" phenomenon response elastically to small strains or stresses, but at some critical value of the stress they yield mechanically and exhibit a complex plastic flow. The search of criteria to distinguish the properties of the material before and after the yield was long and futile; none of the standard signatures like correlation functions, Voronoi tesselations or any other "structural" measure succeeded to clarify the difference between pre-yield and post-yield configurations. I willexplain in this talk how to construct a new order parameter that allows us to show that the yield phenomenon is a bona-fide first order thermodynamic phase transition, shedding an entirely new light on the phenomenon. Materials that exhibit a "yield" phenomenon response elastically to small strains or stresses, but at some critical value of the stress they yield mechanically and exhibit a complex plastic flow. The search of criteria to distinguish the properties of the material before and after the yield was long and futile; none of the standard signatures like correlation functions, Voronoi tesselations or any other "structural" measure succeeded to clarify the difference between pre-yield and post-yield configurations. I willexplain in this talk how to construct a new order parameter that allows us to show that the yield phenomenon is a bona-fide first order thermodynamic phase transition, shedding an entirely new light on the phenomenon.

A spins-inside quantum processor

Date:
11
Thursday
February
2016
Colloquium
Time: 11:15-12:30
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Lieven Vandersypen
Organizer: Faculty of Physics
Details: 11:00 – coffee, tea, and more
Abstract: A quantum computer holds the promise of solving some problems that are beyond th ...A quantum computer holds the promise of solving some problems that are beyond the reach of the most powerful supercomputers. Due to theoretical and experimental breakthroughs in the last few years, we are now at a point where the feeling grows that a large-scale quantum computer can actually be built. Increasingly, this requires bridging the disciplines, from physics to engineering, materials science and computer science. In this talk, I will present the start-of-the-art in quantum computing and outline the challenges ahead, with a focus on electron spin qubits in semiconductors.

The Revolution of the Kepler Space Mission: Exo-planets, Binaries and circumbinary planets

Date:
04
Thursday
February
2016
Colloquium
Time: 00:00
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Tsevi Mazeh
Organizer: Faculty of Physics
Details: 11:00 – coffee, tea, and more
Abstract: TBA ...TBA

Statistical physics of systems when all particles are different

Date:
01
Monday
February
2016
Lecture / Seminar
Time: 14:15
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Dino Osmanovic
Organizer: Department of Physics of Complex Systems
Abstract: Many real world systems contain a multiplicity of interactions, however, this co ...Many real world systems contain a multiplicity of interactions, however, this complexity is usually difficult to capture using statistical physics. In this talk the "All Particles are Different" (APD) model is introduced, where the energy with which any pair of particles in an ensemble interact is some quenched random variable. We first present results of simulations of APD systems and then discuss some more theoretical aspects using simplified lattice APD models.

Permanence and Time irreversibility for particles in turbulence

Date:
25
Monday
January
2016
Lecture / Seminar
Time: 14:15
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Ana Frishman
Organizer: Department of Physics of Complex Systems
Abstract: Turbulent flows are ubiquitous in nature, present in the atmosphere, the ocean ... Turbulent flows are ubiquitous in nature, present in the atmosphere, the oceans, in industrial flows and also in one's own bathtub. From an abstract point of view, turbulence is an elemental problem in out-of-equilibrium statistical mechanics. The flow is driven out of equilibrium by forcing and dissipation acting on disparate scales, forming a chaotic motion that spans many interacting scales. Particles placed in a turbulent flow are therefore driven by an out-of-equilibrium fluctuating medium. I will discuss how the breaking of time reversibility of the flow manifests itself in the dynamics of such particles, focusing on tracers following the turbulent velocity field. I will present exact results for time irreversibility of pair dynamics in incompressible as well as compressible flows. For the latter there is an unexpected jump in the dynamics when time is reversed. For the former, I will describe the existence of an all time statistical conservation law for pair dispersion at small scales. In two dimensional or Hamiltonian flows, this conservation law is extended to an exact relation for the probability distribution function of the finite-time Lyapunov exponent. I will show that it can be interpreted as a fluctuation relation in phase space. Lastly, I will review how time irreversibility can be measured for a single particle and will discuss the application of this idea to a simple model of turbulence flow

Symmetry Breaking in Topological Phases of Condensed Matter

Date:
13
Wednesday
January
2016
Lecture / Seminar
Time: 13:15-14:30
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Joe Checkelsky
Organizer: Department of Condensed Matter Physics
Abstract: Topological Insulators (TIs) are a newly discovered class of materials in which ...Topological Insulators (TIs) are a newly discovered class of materials in which symmetry-protected conducting modes exist on the surface of a bulk insulator. They hold promise for realizing a variety of fundamentally interesting and technologically relevant electronic phases, ranging from quantized magnetoelectric effects to device structures that support extremely high thermoelectric performance. Surprisingly, removing symmetries from these materials – including those that underlie their fundamental protection – has proven to be on the most incisive ways of examining TIs and reaching towards these exotic electronic behaviors. I will discuss our materials oriented approach to breaking symmetry in TIs and the new behavior is has uncovered with a focus on emergent quantum Hall phases.

A NEW LOOK AT CAUSALITY CONSTRAINTS IN QUANTUM FIELD THEORY

Date:
12
Tuesday
January
2016
Lecture / Seminar
Time: 10:30-12:00
Lecturer: THOMAS HARTMAN
Organizer: Department of Particle Physics and Astrophysics
Details: 10:20 Gathering and coffee
Abstract: Causality fixes the signs of certain coupling constants in effective field theor ...Causality fixes the signs of certain coupling constants in effective field theory. I will show how these constraints follow from a causality sum rule for position-space correlators, and combine this method with the conformal bootstrap to derive new constraints on strongly interacting CFTs. Causality of spinning operators is related to the Hofman-Maldacena conditions for positive energy in conformal collider physics. I will also discuss applications to holography.

Michaelis-Menten kinetics: a universal approach to first passage under stochastic restart

Date:
11
Monday
January
2016
Lecture / Seminar
Time: 14:15
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Shlomi Reuveni
Organizer: Department of Physics of Complex Systems
Abstract: In 1913 Michaelis & Menten published a seminal paper in which they presented a m ...In 1913 Michaelis & Menten published a seminal paper in which they presented a mathematical model of an enzymatic reaction and demonstrated how it can be utilized for the analysis and interpretation of kinetic data. More than a century later, the work of Michaelis & Menten is considered classic textbook material, and their reaction scheme is widely applied both in and out of its original context. At its very core, the scheme can be seen as one which describes a generic first passage time process that has further become subject to stochastic restart. This context free standpoint is not the standard one but I will explain how it has recently allowed us to treat a wide array of seemingly unrelated processes on equal footing, and how this treatment has unified, altered, and deepened our view on single-molecule enzymology, kinetic proof-reading and complex search processes. Newly opened opportunities for theoretical and experimental research will also be discussed.

Two new perspectives on high-latitude atmospheric temperature profiles and their sensitivity to climate change

Date:
10
Sunday
January
2016
Lecture / Seminar
Time: 11:00
Location: Sussman Family Building for Environmental Sciences
Lecturer: Timothy Cronin
Organizer: Department of Earth and Planetary Sciences
Abstract: The high-latitude vertical structure of temperature is poorly understood, yet is ...The high-latitude vertical structure of temperature is poorly understood, yet is an important factor in the polar amplification of climate change. To better understand the high-latitude lapse rate and its sensitivity to various forcings, we explore two perspectives on the high-latitude temperature structure. The first is the Lagrangian perspective of Arctic air formation. We prescribe the initial sounding of the atmosphere representing an air column starting over the ocean, then allow the air mass to evolve for two weeks in the absence of any solar heating and with a very low heat capacity surface underneath (representing the movement of the air column over high-latitude sea ice or a continental interior). Using a single-column model, we find that a low-cloud feedback slows cooling of the surface and amplifies continental warming, increasing the continental surface air temperature by roughly two degrees for each degree increase of the initial maritime surface air temperature. We discuss extension with a 2D cloud-resolving model, and applications to past and future warm climates. The second is the Eulerian perspective of radiative-advective equilibrium. High latitude temperature profiles are generally stable to convection, with frequent surface-based inversions, especially in winter. Such profiles result from the stabilizing influences of advective heat flux convergence and atmospheric solar absorption, which dominate over the destabilizing influences of surface solar absorption and subsurface heating. We formulate an analytical model for the high-latitude temperature profile, using prescribed heat flux convergence and either gray- or windowed-gray thermal radiative transfer. We discuss how climate feedbacks in this state depend on the type of forcing, and compare temperature feedbacks in high-latitude radiative-advective equilibrium to the more familiar case of low-latitude radiative-convective equilibrium.

Chemical Physics Department Guest Seminar

Date:
06
Wednesday
January
2016
Lecture / Seminar
Time: 14:00
Title: Enhanced Ultracold Molecule Formation with Shaped Nanosecond Chirped Pulses
Location: Perlman Chemical Sciences Building
Lecturer: Prof Phillip L. Gould
Organizer: Department of Chemical and Biological Physics
Abstract: Ultracold molecules are currently a topic of great interest in AMO physics. One ...Ultracold molecules are currently a topic of great interest in AMO physics. One method for forming such molecules is photoassociation, where two colliding atoms absorb a photon and are bound into an excited molecule. We examine a variation of this process in Rb2, using frequency-chirped light on the nanosecond time scale. In the case of a positive chirp, the photoassociation can be followed by stimulated emission into a high vibrational level of the lowest-lying (metastable) triplet state. We show that this two-step process can be enhanced by a judicious shape of the chirp. Quantum simulations of the molecular formation are not only in good agreement with the experimental results, but also give insight into the enhancement mechanism.

Preparing for the discovery of dark-matter

Date:
06
Wednesday
January
2016
Lecture / Seminar
Time: 11:00-12:30
Lecturer: Joachim Brod
Organizer: Department of Particle Physics and Astrophysics
Details: 10:45 Refreshments 12:30 Lunch
Abstract: Dark matter (DM) is one of the most intriguing open problems in modern particle- ...Dark matter (DM) is one of the most intriguing open problems in modern particle- and astrophysics. Direct, indirect, and collider searches have not yet conclusively established the particle nature of dark matter. After a short overview of dark-matter physics, I will focus on recent theoretical efforts to increase the discovery potential of dark-matter searches. If dark matter indeed has particle nature, then direct detection via scattering on atomic nuclei is one of the most promising discovery channels. Effective field theories (EFT) are the appropriate framework to describe the scattering process, involving physics at very different energy scales. I will show that radiative corrections can have a large impact on the interpretation of data, and stress the importance of a consistent EFT framework. DM searches at particle colliders provide complementary information. If the relic abundance of dark matter is determined by co-annihilation processes in the early universe, this can lead to to characteristic signatures at the LHC. I will discuss these signatures in general terms and point out that not all of them are covered by current serches. Finally, I will illustrate the general strategy with a specific case study, where the coannihilation process is mediated by a scalar leptoquark. I will briefly discuss cosmological probes, collider searches, and constraints from precision physics.

Using a Confocal Rheoscope to Investigate Soft Squishy Materials

Date:
04
Monday
January
2016
Lecture / Seminar
Time: 14:15
Location: Edna and K.B. Weissman Building of Physical Sciences
Lecturer: Itai Cohen
Organizer: Department of Physics of Complex Systems
Abstract: Who among us has not spent countless hours squeezing, rubbing, and smushing gooe ...Who among us has not spent countless hours squeezing, rubbing, and smushing gooey substances like, tooth paste, silly putty, corn starch, and even bodily fluids between our fingers? If we could magnify our view and look deep within the substances we are handling what structures would we find? How, do these structures lead to the fascinating mechanical properties that we experience on the scale of our fingers. In this talk, I will focus on the behavior of colloidal suspensions that serve as a powerful model system capable of exhibiting many of these behaviors. I will discuss how we use confocal imaging in combination with Parameter Extraction from Reconstruction of Images (PERI) to locate micron sized particle positions down to a single nanometer, stress assessment from local structural anisotropy (SALSA) to image stresses at the single particle scale, and a newly developed confocal rheoscope to simultaneously exert strains and measure the macroscale suspension response. The phenomena I will discuss range from using the Green Kubo Fluctuation dissipation theorem to measure a quiescent suspensions viscosity, to uncovering the secret behind the shear thickening properties of Oobleck.

The Dark Energy Survey: more than Dark Energy

Date:
03
Sunday
January
2016
Lecture / Seminar
Time: 11:00-12:00
Location: Nella and Leon Benoziyo Physics Building
Lecturer: Ofer Lahav
Organizer: Nella and Leon Benoziyo Center for Astrophysics
Abstract: The talk will present new expected and unexpected results from the Dark Energy S ...The talk will present new expected and unexpected results from the Dark Energy Survey beyond cosmological studies: e.g. solar system objects, Milky Way companions, galaxy clusters, and high-redshift objects.