Quantum Encounters Seminar

Quantum Information, Condensed Matter, Quantum Field Theory


A seminar organized by Vasily Pestun and Slava Rychkov

Pour être informé des prochains séminaires vous pouvez vous abonner à la liste de diffusion.
Ecrivez un mail à sympa@listes.math.cnrs.fr avec comme sujet: “subscribe quantum_encounters_seminar PRENOM NOM”.
(indiquez vos propres prénom et nom) et laissez le corps du message vide.

Schedule

30th Nov, 2021Sebastian Mizera TBA
23rd Nov, 2021Dominic Else TBA
16th Nov, 2021Dalimil Mazáč TBA
9th Nov, 2021Andrei B. Bernevig TBA
2nd Nov, 2021Jeongwan Haah TBA
26th Oct, 2021Ryan Thorngren TBA
18th Oct, 2021Adam Nahum Measurement Phase Transitions and the Statistical Mechanics of Tree Tensor Networks
5th Oct, 2021Yoshiko Ogata Classification of Gapped Ground State Phases in Quantum Spin Systems
1st Jun, 2021Peter C.W. Holdsworth Emergence: from spins to charges
27th Apr, 2021Anton Kapustin Noncommutative Geometry of Quantum Lattice Models and the Higher Berry Phase

30th November, 2021 - 16:00 Sebastian Mizera (IAS Princeton)

TBA

23rd November, 2021 - 16:00 Dominic Else (Harvard)

TBA

16th November, 2021 - 16:00 Dalimil Mazáč (IAS Princeton)

TBA

9th November, 2021 - 16:00 Andrei B. Bernevig (Princeton)

TBA

2nd November, 2021 - 17:00 Jeongwan Haah (Microsoft Research)

TBA

26th October, 2021 - 16:00 Ryan Thorngren (Harvard Univ.)

TBA

18th October, 2021 - 10:30 Adam Nahum (ENS Paris)

Measurement Phase Transitions and the Statistical Mechanics of Tree Tensor Networks

A many-body quantum system that is continually monitored by an external observer can be in two distinct dynamical phases, distinguished by whether or not repeated local measurements (throughout the bulk of the system) prevent the build-up of long-range quantum entanglement. I will describe the key features of such “measurement phase transitions” and sketch theoretical approaches to their critical properties that make connections with topics in classical statistical mechanics, such as percolation and disordered magnetism. Finally I will discuss random tensor networks with a tree geometry. These arise in a simple limit of the measurement problem, and they show an entanglement transition that can be solved exactly by a mapping to a problem of traveling waves.

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IHES Covid-19 regulations:

- all the participants who will attend the event in person will have to keep their mask on in indoor spaces
and where the social distancing is not possible;
- speakers will be free to wear their mask or not at the moment of their talk if they feel more comfortable
without it;
- Up to 25 persons in the conference room, every participant will be asked to be able to provide a health pass
- Over 25 persons in the conference room, every participant will be asked to provide a health pass which will
be checked at the entrance of the conference room.

==================================================================

Pour être informé des prochains séminaires vous pouvez vous abonner à la liste de diffusion en écrivant un mail à sympa@listes.math.cnrs.fr avec comme sujet: "subscribe quantum_encounters_seminar PRENOM NOM"
(indiquez vos propres prénom et nom) et laissez le corps du message vide.

5th October, 2021 - 10:00 Yoshiko Ogata (Univ. Tokyo)

Classification of Gapped Ground State Phases in Quantum Spin Systems

Recently, classification problems of gapped ground state phases attract a lot of attention in quantum statistical mechanics. We explain about operator algebraic approach to these problems.
 

Participer à la réunion Zoom
https://us02web.zoom.us/j/89796579935?pwd=Ukt3R1VxUFdORHZENHJyN0k3R3Radz09

ID de réunion : 897 9657 9935
Code secret : 459425

Pour être informé des prochains séminaires vous pouvez vous abonner à la liste de diffusion en écrivant un mail à sympa@listes.math.cnrs.fr avec comme sujet: "subscribe quantum_encounters_seminar PRENOM NOM"
(indiquez vos propres prénom et nom) et laissez le corps du message vide.

1st June, 2021 - 16:00 Peter C.W. Holdsworth (Ecole Normale Supérieure de Lyon)

Emergence: from spins to charges

Emergence is a major buzz word of our times. My working definition, which gives plenty of room for manoeuvre is: the appearance of many body phenomena of higher symmetry than that of the Hamiltonian and degrees of freedom at the microscopic level.

In this colloquium I will discuss a topical example - the frustrated magnetic material, spin ice. Here, to an excellent approximation a classical field theoretic description with continuous U(1) symmetry emerges from Ising like degrees of freedom. The associated quasi-particles appear to be freely moving magnetic charge - magnetic monopoles - and the system behaves as a magnetic Coulomb fluid in the grand canonical ensemble with intrinsic topological properties. With the addition of quantum fluctuations the emergent magneto-statics develops further into a complete analogue of quantum electrodynamics. I will aliment this discussion with experimental results from a wide range of systems.


https://us02web.zoom.us/j/85270888147?pwd=aXdOVXBTSmNEU00vVFE2bXhqdE5vdz09

ID de réunion : 852 7088 8147
Code secret : 276852

27th April, 2021 - 17:00 Anton Kapustin (Caltech)

Noncommutative Geometry of Quantum Lattice Models and the Higher Berry Phase

Recently methods of quantum statistical mechanics have been fruitfully applied to the study of phases of quantum lattice systems at zero temperature. For example, a rigorous definition of a Short-Range Entangled phase of matter has been given and a classification of such phases in one spatial dimension has been achieved. I will discuss some of these developments, focusing on the topology and geometry of the space of Short-Range Entangled states. According to a conjecture of A. Kitaev, these spaces form a loop spectrum in the sense of homotopy theory. This conjecture implies that to any family of Short-Range entangled states in one dimension one can associate a gerbe on the parameter space. I will show how to construct such a gerbe. Thе curvature of this gerbe is a closed 3-form with quantized periods and can be regarded as a higher-dimensional generalization of the curvature of the Berry connection.


https://us02web.zoom.us/j/81778962715?pwd=QnpNS2ErSnBCTWRYUHphd1VMMysyZz09

ID de réunion : 817 7896 2715
Code secret : 800452