COVID-19 information for PI Residents and Visitors
Scientific Areas:
In recent years, much progress was achieved in realizing highly controlled and coherent many-body systems. Examples of such systems include systems of ultra-cold atoms, molecules, systems of NV-centers in diamond, and superconductiong quibits. These remarkable experimentally advances pose a conceptually new set of theoretical questions regarding the universal laws describing the evolution and relaxation of closed many-body systems. This workshop will cover the most exciting recent theoretical developments in non-equilibrium many-body physics. Focus topics include thermalization in integrable and non-integrable strongly interacting systems, thermalization breakdown, perodically driven systems, and many-body localization in systems with quenched disorder. We will discuss key changes in the field and identify the possible roles to their solution.
To register for this event, click here.
Ehud Altman, Weizmann Institute of Science
Jean-Sebastian Caux, University of Amsterdam
Luca D'Alessio, Boston University
Eugene Demler, Harvard University
Jens Eisert, Freie University Berlin
Fabian Essler, University of Oxford
Matthew Fisher, University of California, Santa Barbara
John Imbrie, University of Virginia
Robert Konik, Brookhaven National Laboratory
Aditi Mitra, New York University
Arijeet Pal, Harvard University
Anatoli Polkovnikov, Boston University
Marcos Rigol, Pennsylvania State University
Lea Santos, Yeshiva University
Antonello Scardicchio, Princeton University
Alessandro Silva, University of Trieste
Ronen Vosk, Weizmann Institute of Science
- Dmitry Abanin, Perimeter Institute
- Ehud Altman, Weizmann Institute of Science
- Oleg Boulanov, Laval University
- Michael Brockmann, University of Amsterdam
- Jean-Sebastien Caux, University of Amsterdam
- Juan Carrasquilla, Perimeter Institute
- Anushya Chandran, Perimeter Institute
- Eugene Demler, Harvard University
- Jens Eisert, Freie University Berlin
- Fabian Essler, University of Oxford
- Matthew Fisher, University of California, Santa Barbara
- Yimin Ge, Perimeter Institute
- John Imbrie, University of Virginia
- Isaac Kim, Perimeter Institute
- Robert Konik, Brookhaven National Laboratory
- William Witczak-Krempa, Perimeter Institute
- Oliver Landon-Cardinal, California Institute of Technolog
- Keith Lee, Perimeter Institute
- Ipsita Mandal, Perimeter Institute
- Aditi Mitra, New York University
- Khadijeh Najafi, Georgetown University
- Arijeet Pal, Harvard University
- Zlatko Papic, Perimeter Institute
- Anatoli Polkovnikov, Boston University
- Marcos Rigol, Pennsylvania State University
- Subir Sachdev, Harvard University
- Lea Santos, Yeshiva University
- Luiz Santos, Perimeter Institute
Antonello Scardicchio, Princeton University - Maksym Serbyn, Massachusetts Institute of Technology
- Alessandro Silva, University of Trieste
- Miles Stoudenmire, Perimeter Institute
- Jonathan Torres-Herrera, Yeshiva University
- Guifre Vidal, Perimeter Institute
- Ronen Vosk, Weizmann Institute of Science
Monday, May 12^{th}, 2014
Time |
Event |
Location |
8:30 – 9:00am |
Registration |
Reception |
9:00 – 9:05am |
Welcome and Opening Remarks |
Bob Room |
9:05 – 10:00am |
Eugene Demler, Harvard University TBA |
Bob Room |
10:00 – 10:30am |
Coffee Break |
Bistro – 1^{st} Floor |
10:30 – 11:25am |
Marcos Rigol, Pennsylvania State University Quantum Quenches in Thermodynamic Limit |
Bob Room |
11:25 – 12:20pm |
Jens Eisert, Freie University Berlin Dynamical analogue quantum simulators |
Bob Room |
12:30 – 2:00pm |
Lunch |
Bistro – 2^{nd} Floor |
2:00 – 3:30pm |
Informal Discussions |
Bob Room |
3:30 – 4:00pm |
Coffee Break |
Bob Room |
4:00 – 5:00pm |
Discussion: Experiments |
Bob Room |
Tuesday, May 13^{th}, 2014
Time |
Event |
Location |
9:00 – 10:00am |
Anatoli Polkovnikov TBA |
Bob Room |
10:00 – 10:30am |
Coffee Break |
Bistro – 1^{st} Floor |
10:30 – 11:25am |
Fabian Essler, University of Oxford Light-Cone Effects after Quantum Quenches and Excitations at Finite Entropy |
Bob Room |
11:25 – 12:20pm |
Luca D`Alessio Long-time behavior of periodically driven isolated interacting quantum systems |
Bob Room |
12:20 – 12:30pm |
Conference Photo |
Atrium |
12:30 – 2:00pm |
Lunch Break |
Bistro – 2^{nd} Floor |
2:00 – 3:30pm |
Condensed Matter Seminar Federico Becca, SISSA TBA Informal Discussion – Quantum Many Body Dynamics |
Bob Room
Alice Room |
3:30 – 4:00pm |
Coffee Breaks |
Bistro – 1^{st} Floor |
4:00 – 5:00pm |
Discussion – Driven Systems |
Bob Room |
Wednesday, May 14, 2014
Time |
Event |
Location |
9:00 – 10:00am |
Ehud Altman Localization and topology protected quantum coherence at the edge of 'hot' matter |
Bob Room |
10:00 – 10:30am |
Coffee Break |
Bistro – 1^{st} floor |
10:30 – 11:25am |
Arijeet Pal, Harvard University TBA |
Bob Room |
11:25 – 12:30pm |
John Imbrie, University of Virginia A Rigorous Result on Many-Body Localization |
Bob Room |
12:30 – 2:00pm |
Lunch |
Bistro – 2^{nd} Floor |
2:00 – 3:30pm |
Colloquium Claudia de Rham What can we learn from modifying gravity |
Theatre |
3:30 – 4:00pm |
Break |
Bistro – 1^{st} Floor |
4:00 – 5:00pm |
Discussion – Many-Body Localization |
Bob Room |
5:00 Onwards |
Banquet |
Bistro – 2^{nd} Floor |
Thursday, May 15^{th}, 2014
Time |
Event |
Location |
9:00 – 10:00am |
Jean-Sebastien Caux, University of Amsterdam Exact solutions for quenches in 1d Bose gases and quantum spin chains. |
Bob Room |
10:00 – 10:30am |
Coffee Break |
Bistro – 1^{st} Floor |
10:30 – 11:25am |
Ronen Vosk, Weizmann Institute of Science Renormalization group theory of dynamics in many-body localized states and the many-body localization transition |
Bob Room |
11:25 – 12:30pm |
Matthew Fisher, UC Santa Barbara Can Eigenstate Thermalization Breakdown |
Bob Room |
12:30 – 2:00pm |
Lunch |
Bistro – 2^{nd} Floor |
2:00 – 3:30pm |
Antonello Scardicchio, Princeton University TBA |
Bob Room |
3:30 – 4:00pm |
Coffee Break |
Bistro – 1^{st} Floor |
4:00 – 5:00pm |
Discussion – Localization Without Disorder |
Bob Room |
5:00 Onwards |
Pub Night |
Bistro – 1^{st} Floor |
Friday, May 16^{th}, 2014
Time |
Event |
Location |
9:00 – 10:00am |
Robert Konik, Brookhaven National Laboratory Glimmers of a Quantum KAM Theorem: Insights from Quantum Quenches in One Dimensional Bose Gases |
Bob Room |
10:00 – 10:30am |
Coffee Break |
Bistro – 1^{st} floor |
10:30 – 11:25am |
Aditi Mitra, New York University Quench dynamics in interacting and disordered field theories in one-dimension |
Bob Room |
11:25 – 12:20pm |
Lea Santos, Yeshiva University General Features of the Relaxation Dynamics of Isolated Interacting Quantum Systems |
Bob Room |
12:20 – 12:30pm |
Concluding Remarks |
Bob Room |
12:30 – 2:00pm |
Lunch |
Bistro – 2^{nd} Floor |
2:00 – 3:30pm |
Informal Discussions |
Bob Room |
3:30 – 4:00pm |
Coffee Break |
Bistro – 1^{st} Floor |
4:00 – 6:00pm |
Informal Discussions |
Bob Room |
Luca D`Alessio, Boston University
We show that generic interacting quantum systems, which are isolated and finite, periodically driven by sudden quenches exhibit three physical regimes. For short driving periods the Floquet Hamiltonian is well approximated by the time-averaged Hamiltonian, while for long periods the evolution operator exhibits properties of random matrices of a Circular Ensemble (CE). In-between, there is a crossover
regime. We argue that, in the thermodynamic limit and for nonvanishing driving periods, the evolution operator always exhibits properties of CE random matrices. Consequently, driving leads to infinite temperature at infinite time and to an unphysical Floquet Hamiltonian.
Ehud Altman, Weizmann Institute of Science
For the Kagome lattice, we find that a gapless U(1) spin liquid with Dirac cones
is competitive with previously proposed gapped spin liquids when only the nearest-neighbor antiferromagnetic interaction is present.[3,4] The inclusion of a next-nearest-neighbor term lead to a Z_2 gapped spin liquid,[5] in agreement with density-matrix renormalization group calculations.[6] In the Heisenberg model on the square lattice with both nearest- and next-nearest-neighbor interactions, a Z_2 spin liquid with gapless spinon excitations is stabilized in the frustrated regime.[7] This results are (partially) in agreement with recent density-matrix renormalization group on large cylinders.[8]
[1] X.-G. Wen, Phys. Rev. B {\bf 44}, 2664 (1991); Phys. Rev. B {\bf 65}, 165113 (2002).
[2] S. Sorella, Phys. Rev. B {\bf 64}, 024512 (2001).
[3] Y. Iqbal, F. Becca, S. Sorella, and D. Poilblanc, Phys. Rev. B 87, 060405(R) (2013).
[4] Y. Iqbal, D. Poilblanc, and F. Becca, Phys. Rev. B 89, 020407(R) (2014).
[5] W.-J. Hu, Y. Iqbal, F. Becca, D. Poilblanc, and D. Sheng, unpublished.
[6] H.-C. Jiang, Z. Wang, and L. Balents, Nat. Phys. 8, 902 (2012);
S. Yan, D. Huse, and S. White, Science 332, 1173 (2011).
[7] W.-J. Hu, F. Becca, A. Parola, and S. Sorella, Phys. Rev. B 88, 060402(R) (2013).
[8] S.-S. Gong, W.Z., D.N. Sheng, O.I. Motrunich, and M.P.A. Fisher, arXiv:1311.5962 (2013).
Jens Eisert, Freie University Berlin
Dynamical analogue quantum simulators
Complex quantum systems out of equilibrium are at the basis of a number of long-standing questions in physics. This talk will be concerned on the one hand with recent progress on understanding how quantum many-body systems out of equilibrium eventually come to rest, thermalise and cross phase transitions, on the other hand with dynamical analogue quantum simulations using cold atoms [1-4]. In an outlook, we will discuss the question of certification of quantum simulators, and will how this problem also arises in other related settings, such as in Boson samplers [5,6].
[1] S. Braun, M. Friesdorf, S. S. Hodgman, M. Schreiber, J. P. Ronzheimer, A. Riera, M. del Rey, I. Bloch, J. Eisert, U. Schneider, arXiv:1403.7199.
[2] M. Kliesch, M. Kastoryano, C. Gogolin, A. Riera, J. Eisert, arXiv:1309:0816.
[3] S. Trotzky, Y.-A. Chen, A. Flesch, I. P. McCulloch, U. Schollwoeck, J. Eisert, I. Bloch, Nature Physics 8, 325 (2012).
[4] A. Riera, C. Gogolin, M. Kliesch, J. Eisert, in preparation (2014).
[5] C. Gogolin, M. Kliesch, L. Aolita, J. Eisert, in preparation (2014) and arXiv:1306.3995.
[6] S. Aaronson, A. Arkhipov, arXiv:1309.7460.
Fabian Essler, University of Oxford
Light-Cone Effects after Quantum Quenches and Excitations at Finite Entropy
Matthew Fisher, University of California, Santa Barbara
Can Eigenstate Thermalization Breakdown without Disorder?
In my talk I will discuss the nature of the many-body localization-delocalization (MBLD) transition as a function of energy denisty in the quantum random energy model (QREM). QREM provides a mean-field description of the equilibrium spin glass transition. We show that it further exhibits a many-body mobility edge when viewed as a closed quantum system. The mean-field structure of the model allows an analytically tractable description of the MBLD transition. I will also comment on the nature of the critical states in this mean-field model.
This opens the possibility of developing a mean-field theory of this interesting dynamical phase transition.
(Lea Santos) General Features of the Relaxation Dynamics of Isolated Interacting Quantum Systems
We consider isolated interacting quantum systems that are taken out of equilibrium instantaneously (quenched). We study numerically and analytically the probability of finding the initial state later on in time (the so-called fidelity or Loschmidt echo), the relaxation time of the system, and the evolution of few-body observables. The fidelity decays fastest for systems described by full random matrices, where simultaneous many-body interactions are implied.
Quench dynamics in interacting and disordered field theories in one-dimension
I will present results for the quench dynamics of one-dimensional interacting bosons under two circumstances. One is when the bosons are in the vicinity of the superfluid-Mott quantum critical point, while the second is when the bosons are in a disordered potential which can drive the system into a Bose glass phase. I will show that the dynamics following a quench can be quite complex by being characterized by three regimes.
(Robert Konik) Glimmers of a Quantum KAM Theorem: Insights from Quantum Quenches in One Dimensional Bose Gases
We consider quantum quenches in one dimensional Bose gases where we prepare the gas in the ground state of a parabolic trap and then release it into a small cosine potential. This cosine potential breaks the integrability of the 1D gas which absent the potential is described by the Lieb-Liniger model. We explore the consequences of this cosine potential on the thermalization of the gas. We argue that the integrability breaking of the cosine does not immediately lead to ergodicity inasmuch as we demonstrate that there are residual quasi-conserved quantities post-quench.
TBA
Can Eigenstate Thermalization Breakdown without Disorder?
We describe a new diagnostic for many-body wavefunctions which generalizes the spatial bipartite entanglement entropy. By was of illustration, for a two-component wavefunction of heavy and light particles, a partial (projective) measurement of the coordinates of the heavy (but not light) particles is first performed, and then the entanglement entropy of the projected wavefunction for the light particles is computed.
Universal dynamics and topological order in many-body localized states
It has been argued recently that, through a phenomenon of many-body localization, closed quantum systems subject to sufficiently strong disorder would fail to thermalize. In this talk I will describe a real time renormalization group approach, which offers a controlled description of universal dynamics in the localized phase. In particular it explains the ultra-slow entanglement propagation in this state and identifies the emergent conserved quantities which prevent thermalization.
(Jean-Sebastien Caux) Exact solutions for quenches in 1d Bose gases and quantum spin chains
A Rigorous Result on Many-Body Localization
I will discuss a proof of many-body localization for a one-dimensional spin chain with random local interactions. The proof depends on a physically reasonable assumption that limits the amount of level attraction in the system. I construct a sequence of local rotations that completely diagonalizes the Hamiltonian and exhibits the local degrees of freedom.
Many-body mobility edge in a mean-field quantum spin-glass
Isolated, interacting quantum systems in the presence of strong disorder can exist in a many-body localized phase where the assumptions of equilibrium statistical physics are violated. On tuning either the parameters of the Hamiltonian or the energy density, the system is expected to transition into the ergodic phase. While the transition at "infinite temperature" as a function of system parameters has been found numerically but, the transition tuned by energy density has eluded such methods.
Localization and topology protected quantum coherence at the edge of 'hot' matter
Topological phases are often characterized by special edge states confined near the boundaries by an energy gap in the bulk. On raising temperature, these edge states are lost in a clean system due to mobile thermal excitations. Recently however, it has been established that disorder can localize an isolated many body system, potentially allowing for a sharply defined topological phase even in a highly excited state.I will show this to be the case for the topological phase of a one dimensional magnet with quenched disorder, which features spin one-half excitations at the edges.
Pages
Scientific Organizers:
Dmitry Abanin, Perimeter Institute
Anushya Chandran, Perimeter Institute
Zlatko Papic, Perimeter Institute