Quantum many-body systems out-of-equilibrium, Paris

Jan 8, 2024, 8:30 AM → Mar 22, 2024, 8:30 PM Europe/Paris

Institut Henri Poincaré

Thematic program held at the Institut Henri Poincaré.

The conferences, the courses and the seminars of this program will also be accessible online: https://www.ihp.fr/en/live and/or https://univ-cotedazur.zoom.us/j/3777115746?omn=83887855821

Recordings will be available later on: https://www.carmin.tv/en/

 

Registration is free but mandatory.

It does not give you an automatic registration for the workshops, so please also register for each workshop you wish to attend.

 

Presentation of the trimester:

The theoretical study of quantum many-body systems is a challenging task due to the amazing complexity induced by the huge number of degrees of freedom of these systems. Equilibrium properties of such systems have been deeply studied in the last decades. In particular, at one-dimension, it is possible for some systems to have access to exact solutions, for instance, within Bethe Ansatz methods. Where exact solutions are not accessible, it is possible to use field theoretical approaches or numerical techniques. Even if, formally, it is possible to have exact solutions both at zero and finite temperature, the case of finite (low) temperature can be exceptionally complicated for quantum mixtures, where one should solve an infinite number of coupled equations following a Bethe Ansatz scheme.  Although equilibrium at zero temperature is an ideal situation, most of the physical systems are out-of-equilibrium and/or at finite temperature. Indeed in the last years, several communities have concentrated their effort in the study  of quantum many-body systems out-of-equilibrium, both close and open. From the mathematical point of view, a lot of progress has been made recently regarding the asymptotic expansion of the many-body Schrödinger equation in macroscopic limits (correlation energies, quantum fluctuations...). Important challenges remain, in particular as regards applications to scaling limits most relevant for experiments, such as the so-called Gross-Pitaevskii limit for bosons.

The aim of this trimester is to give the possibility to the scientists of these different communities to meet, share their advances, create new collaborations and make theoretical frames and mathematical tools progress. 
 

Confirmed participants: 

• Roberta Citro (Salerno University)
• Chitra R. (ETH, Zurich)
• Eugene Demler (ETH Zurich)
• Fabian Essler (University of Oxford)
• Dimitri Gangardt (University of Birmingham)
• Yuval Gefen (Weizmann Institute)
• Pietro Massignan (ICFO Spain)
• Giuseppe Mussardo (SISSA - Trieste)
• Maxim Olshanii (University of Massachusetts)
• Tomaz Prosen (Université de Ljubljana)
• Yuri Rubo (Universidad Nacional Autonoma de Mexico)
• Marzena Szymanska (University College London)
• Andrea Trombettoni (SISSA - Trieste)

 

Organizing committee:

• Rosario Fazio (ICTP)
• Thierry Giamarchi (University of Geneva)
• Anna Minguzzi (University Grenoble-Alpes, CNRS)
• Patrizia Vignolo (University Côte d'Azur, CNRS)

 

Scientific committee:

• Jean-Sébastien Caux (Amsterdam) 
• Jakob Yngvason (Vienna) 
• Corinna Kollath (Bonn, Germany) 
• Maxim Olshanii (Boston, USA)
• Marcos Rigol (Philadelphia, USA) 
• Païvi Törmä (Aalto University) 
• Nikolaj Thomas Zinner (Aarhus University) 

 

*  to be confirmed

Tue, January 9

1 Lecture: Berry's billiard as a minimal model for a loss of memory of the initial conditions. Restoring the memory and Bethe Ansatz. Instances of integrability.

The course will also be accessible online: https://www.ihp.fr/en/live

Its registration will be accessible (starting from the following week) on https://www.carmin.tv/en/

Speaker: Prof. Maxim Olchanyi (Department of Physics, University of Massachusetts Boston)

Wed, January 10

2 Multiferroics: lattice assisted magneto-electric coupling

A microscopic magneto-electric model is studied in which the coupling between spins
and electric dipoles is mediated by lattice distortions. The magnetic sector is described
by a Heisenberg model coupled directly to the lattice via a standard spin-Peierls term and indirectly to the electric dipole variables via the distortion of the surrounding electronic clouds.
Electric dipoles are described by Ising variables for simplicity. We show that the effective
magneto-electric coupling which arises due to the interconnecting lattice deformations is
quite efficient in one- and two-dimensional arrays. In the 1D case, using bosonization and extensive DMRG numerical simulations we show that for a magnetic field above the spin Peierls gap, a massive polarization switch-off occurs due to the proliferation of soliton pairs.
Introducing further neighbors couplings and single ion anisotropy, the system shows the
"uudd" (or so-called antiphase) magnetic ordering observed in several type II multiferroic
materials. In a bidimensional Ising like case we use extensive Monte Carlo simulations to show a qualitatively similar behaviour.

Speaker: Daniel Carlos Cabra (Physics Department, University of La Plata, Argentine)

Thu, January 11

3 Seminar: Magic Lorenz ratios and Anderson orthogonality catastrophe in out-of-equilibrium quantum simulators

M. N. Kiselev. "Generalized Wiedemann-Franz law in a two-site charge Kondo circuit: Lorenz ratio as a manifestation of the orthogonality catastrophe", Phys. Rev. B 108, L081108 (2023)

Speaker: Mikhail Kiselev (ICTP)

Tue, January 16

4 Lecture: A new arrival to the integrability list: the Shi-Gao-Zhai solution. Mass defects as an integrability breaker: quantum Chirikov criterion for chaos.

The course will also be accessible online: https://www.ihp.fr/en/live

Its registration will be accessible (starting from the following week) on https://www.carmin.tv/en/

Speaker: Maxim Olchanyi (Department of Physics, University of Massachusetts Boston)

Thu, January 18

5 Coherence properties of strongly interacting quantum mixtures in one dimension

The seminar will also be accessible online: https://www.ihp.fr/en/live

Its registrations will be accessible (starting from the following week) on https://www.carmin.tv/en/

Speaker: Mathias Albert (INPHYNI, Universite Cote d'Azur)

Fri, January 19

6 Integrability and truncated spectrum approach for out-of-equilibrium dynamics

The seminar will also be accessible online: https://www.ihp.fr/en/live

Its registration will be accessible (starting from the following week) on https://www.carmin.tv/en/

Speaker: Jean-Sébastien Caux (University of Amsterdam)

Tue, January 23

7 Lecture: Liu-Qi-Zhang-Chen system and Asymmetric Bethe Ansatz

The course will also be accessible online:
https://univ-cotedazur.zoom.us/j/3777115746?omn=83887855821

(https://www.ihp.fr/en/live)

Its registration will be accessible (starting from the following week) on https://www.carmin.tv/en/

Speaker: Maxim Olchanyi (Department of Physics, University of Massachusetts Boston)

Wed, January 24

8 Max-Ent Projected and Restricted Dynamics for Many-Body Quantum Systems

The seminar will also be accessible online: https://www.ihp.fr/en/live and/or https://univ-cotedazur.zoom.us/j/3777115746?omn=83887855821

Recording will be available later on: https://www.carmin.tv/en/

Speaker: Federico Tomás Benito Pérez (Instituto de Física La Plata, IFLP - UNLP/CONICET - Argentina)

FTBP_seminar_abstract.pdf

Thu, January 25

9 Lecture: Number Theory and Physics (I)

In the first lecture we discuss how to experimentally realize a holographic quantum potential which encodes prime numbers (or other desired number sequences) as quantum eigenvalues and how can be addressed question of high complexity in number theory (such as the primality or the factorization of an integer) by means of simple quantum experiments.

The course will also be accessible online: https://www.ihp.fr/en/live and/or https://univ-cotedazur.zoom.us/j/3777115746?omn=83887855821

Recording will be available later on: https://www.carmin.tv/en/

Speaker: Giuseppe Mussardo (SISSA)

Tue, January 30

10 Folded quantum integrable models and deformed W-algebras

(joint work with E. Frenkel and N. Reshetikhin)

We propose a novel quantum integrable model for every non-simply laced simple Lie algebra g. Its spectra correspond to solutions of the Bethe Ansatz equations obtained by folding the Bethe Ansatz equations associated to the simply-laced Lie algebra g′ (corresponding to g). Our construction is motivated by the analysis of the second classical limit of the deformed W-algebra of g. We conjecture, and verify in a number of cases, that the spaces of states of the folded integrable model can be identified with finite-dimensional representations of the Langlands dual (twisted) quantum affine algebra.

The seminar will also be accessible online: https://www.ihp.fr/en/live and/or https://univ-cotedazur.zoom.us/j/3777115746?omn=83887855821

Recording will be available later on: https://www.carmin.tv/en/

Speaker: David Hernandez (Université Paris Cité)

Wed, January 31

11 Polariton Bose-Hubbard dimer: Symmetry breaking, time crystals, chaos, and quantum features

The seminar will also be accessible online: https://www.ihp.fr/en/live and/or https://univ-cotedazur.zoom.us/j/3777115746?omn=83887855821

Recording will be available later on: https://www.carmin.tv/en/

Speaker: Dr Yura Rubo (Instituto de Energías Renovables, UNAM, Mexico)

Thu, February 1

12 Lecture: Number Theory and Physics (II)

In this second lecture we discuss how renown topics of statistical physics and quantum
integrable models, such as brownian motion and Bethe ansataz equations, can shed light on an old standing open problem of number theory such as the Generalised Riemann Hypothesis.

The course will also be accessible online: https://www.ihp.fr/en/live and/or https://univ-cotedazur.zoom.us/j/3777115746?omn=83887855821

Recording will be available later on: https://www.carmin.tv/en/

Speaker: Giuseppe Mussardo (SISSA)

Fri, February 2

13 Bures geodesics and quantum metrology

We study the geodesics on the manifold of mixed quantum states for the Bures metric. It is shown that these geodesics correspond to physical non-Markovian evolutions of the system coupled to an ancilla. Furthermore, we argue that geodesic evolutions are of interest in quantum metrology. In fact, if the unknown parameter is a phase shift proportional to the time parametrizing the geodesic, the estimation error obtained by processing the data of measurements on the system is equal to the smallest error that can be achieved from joint detections on the system and ancilla. This means that the ancilla does not carry any information on the parameter. The estimation error can saturate the Heisenberg bound. In addition, the measurement on the system bringing most information on the parameter is parameter-independent and can be determined in terms of the intersections of the geodesic with the boundary of quantum states.

The seminar will also be accessible online: https://www.ihp.fr/en/live

Its registration will be accessible (starting from the following week) on https://www.carmin.tv/en/

Speaker: Dominique Spehner (Universidad de Concepcion, Chili)

Mon, February 5

14 "Quantum simulators" workshop (9:00-18:00)

https://indico.math.cnrs.fr/event/8996/timetable/#20240205.detailed

Tue, February 6

15 "Quantum simulators" workshop (9:15-18:00)

https://indico.math.cnrs.fr/event/8996/timetable/#20240205.detailed

Wed, February 7

16 "Quantum simulators" workshop (9:15:19:00)

https://indico.math.cnrs.fr/event/8996/timetable/#20240205.detailed

Thu, February 8

17 "Quantum simulators" workshop (9:15-18:00)

https://indico.math.cnrs.fr/event/8996/timetable/#20240205.detailed

18 Carte Blanche "La métrologie quantique et ses applications"

Seminar in french, for all audiences, at the Maison Poincaré

Registration is mandatory
https://billetterie-maison-poincare.ihp.fr/evenements/conferences-cartes-blanche/la-metrologie-quantique

Speaker: Dominique Spehner (Universidad de Concepcion, Chili)

Fri, February 9

19 "Quantum simulators" workshop (9:15-16:30)

https://indico.math.cnrs.fr/event/8996/timetable/#20240205.detailed

Tue, February 13

20 Dissipative transitions in light matter systems

In many quantum engineered systems, desired static hamiltonians are realised in the rotating frame i.e., the systems are inherently driven periodically in time. What happens, when such systems talk to a dissipative environment which is truly static ?
In this talk, focusing on cold atomic gases coupled to quantized light modes, I will show how the relative rotation between the system in a rotating frame and a dissipative bath can dramatically alter the phase diagram and lead to rich phenomenology.

Speaker: Ramasubramanian Chitra (ETH Zurich)

Wed, February 14

21 Lecture I "On exactly solvable dynamics in quantum circuits"

Speaker: Prof. Tomaž Prosen (University of Ljubljana)

Thu, February 15

22 Thermal properties of frustrated quantum magnets

The seminar will also be accessible online: https://www.ihp.fr/en/live

Its registration will be accessible (starting from the following week) on https://www.carmin.tv/en/

Speaker: Frédéric Mila (Ecole Polytechnique Fédérale de Lausanne, Switzerland)

Tue, February 20

23 Coherent states attached to Landau levels on 2D surfaces

Speaker: Zouhaïr Mouayn (Sultan Moulay Slimane University)

Wed, February 21

24 Lecture II "On exactly solvable dynamics in quantum circuits"

Speaker: Tomaž Prosen (University of Ljubljana)

Thu, February 22

25 Grey solitons in the nonlinear Schrödinger equation: quenches, phase-slips and shock waves

Speaker: Romain Dubessy (Laboratoire de physique des lasers UMR7538 CNRS - Université Sorbonne Paris Nord)

Fri, February 23

26 When the intuition betrays or saves: messages from the 1D world (Lecture 1)

Speaker: Serguei Brazovski (LPTMS CNRS, Universite- Paris Saclay)

Mon, February 26

27 When the intuition betrays or saves: messages from the 1D world (Lecture 2)

Speaker: Serguei Brazovski (LPTMS CNRS, Universite- Paris Saclay)

Tue, February 27

28 Topological and out of equilibrium magnetic textures and their effect on itinerant electrons

The physics of topological magnetic textures like skyrmions and bimerons, and in particular the issue of how to isolate and manipulate them individually, is a subject of major importance nowadays in the community of magnetism. We propose a model with a rich phase diagram containing these topological magnetic textures that appear in crystalline, fluid and glassy phases. I'll then discuss the study of this rich magnetic background on conduction electrons that are coupled to the local spins. We study how the different magnetic textures stabilised in this model induce an anomalous Quantum Hall effect. We observe in the ordered skyrmion phase the appearance of Landau levels which persist even in the skyrmion-liquid regime and gradually disappear as the skyrmion density decreases.

The seminars will also be accessible online: https://www.ihp.fr/en/live and/or https://univ-cotedazur.zoom.us/j/3777115746?omn=83887855821

Recording will be available later on: https://www.carmin.tv/en/

Speaker: Pierre Pujol (Université de Toulouse 3, Paul Sabatier)

Wed, February 28

29 Lecture III "On exactly solvable dynamics in quantum circuits"

Speaker: Tomaž Prosen (University of Ljubljana)

Thu, February 29

30 From AL to MBL

So far, most of the work aimed at understanding the many-body localization (MBL) problem has focused on the regime of relatively strong interactions. In this talk, after presenting some aspects of the current state of the field, I will discuss the overlooked regime of weak interactions, which turns out to be quite instructive for getting a better grasp on the MBL problem. I will also discuss very recent results on two-body correlations, which show unique properties to witness an ergodic instability and to test the avalanche theory.

Speaker: Nicolas Laflorencie (LPT Toulouse)

Mon, March 4

31 Some nonequilibrium features of interacting Anderson insulators

Speaker: Zvi Ovadyahu (Racah Institute of Physics, The Hebrew University Jerusalem ISRAEL)

Wed, March 6

32 Lecture IV "On exactly solvable dynamics in quantum circuits"

Speaker: Tomaž Prosen (University of Ljubljana)

Thu, March 7

33 Superfluid Kelvin-Helmholtz instability: suppression due to massive vortex cores, friction and confinement

Speaker: Andrea Richaud (Universitat Politècnica de Catalunya)

Tue, March 12

34 Superfluid fraction of interacting bosonic gases

Speaker: Pietro Massignan (Universitat Politècnica de Catalunya (Barcelona))

Wed, March 13

35 Nonthermal resources and fluctuations in nanoscale engine

Standard thermodynamic machines transform heat into work or vice versa. Macroscopic quantities, like temperatures, quantify the efficiency of their operation. This is different in nanoscale systems—often smaller than the length scales on which thermalisation takes place and where fluctuations can be of the same magnitude as average quantities. In this talk, I will show some properties of nanoelectronic devices, operating as engines, that are unique to the small scales on which they are realized.

I will start by introducing novel relations between charge currents flowing in nanoelectronic conductors and their noise. In contrast to standard fluctuation-dissipation relations, valid in equilibrium, these relations for generic nonequilibrium situations consist in inequalities, setting bounds on the currents that can be obtained given a certain noise level of the signal [1]. This has direct implications on the performance of nanoelectronic engines, complementing recently introduced thermodynamics uncertainty relations [2].

However, noise is not only a nuisance, but noisy resources can be beneficial for the operation of an engine! In the second part of my talk, I will introduce engines working without absorbing heat or work from the resource on average, seemingly violating the second law of thermodynamics [3]. This is possible when the resource has nonthermal properties (namely, it cannot be characterized by a temperature or potential) and requires fluctuations in the input [4].

I will end by giving on outlook on how these unconventional resources could possibly be used in future devices.

[1] L. Tesser and J. Splettstoesser: “Out-of-Equilibrium Fluctuation-Dissipation Bounds”, arXiv:2309.17422

[2] A. C. Barato, U. Seifert: “Thermodynamic Uncertainty Relation for Biomolecular Processes”, Phys. Rev. Lett. 114, 158101 (2015)

[3] R. Sánchez, J. Splettstoesser, R. S. Whitney: “Nonequilibrium System as a Demon”, Phys. Rev. Lett. 123, 216801 (2019)

[4] M. Acciai, L. Tesser, J. Eriksson, R. Sánchez, R. S. Whitney, J. Splettstoesser “Constraints between entropy production and its fluctuations in nonthermal machines”, Phys. Rev. B 109, 075405 (2024)

Speaker: Janine Splettstoesser (Chalmers University of Technology, Gothenburg, Sweden)

Thu, March 14

36 Lossy one-dimensional Bose gases: anomalous decay and collective modes

Speaker: Alberto Biella (CNR-INO)

Mon, March 18

37 Workshop "Driven Quantum systems" (9:00-18:00)

https://indico.math.cnrs.fr/event/8997/

Tue, March 19

38 Workshop "Driven quantum systems" (9:00-18:00)

https://indico.math.cnrs.fr/event/8997/

Wed, March 20

39 Workshop "Driven Quantum Systems" (9:00-18:00)

https://indico.math.cnrs.fr/event/8997/

Thu, March 21

40 Superfluidity from correlations in driven boson systems

We investigate theoretically the superfluidity of a one-dimensional boson system whose hopping energy is periodically modulated with a zero time average, which results in the suppression of first-order single-particle hopping processes. The dynamics of this Floquet-engineered flat-band system is entirely driven by correlations and described by exotic Hamiltonian and current operators. We employ exact diagonalization and compare our results with those of the conventional, undriven Bose-Hubbard system. We focus on the two main manifestations of superfluidity, the Hess-Fairbank effect and
the metastability of supercurrents, with explicit inclusion of an impurity when relevant. Among the novel superfluid features, we highlight the presence of a cat-like ground state, with branches that have opposite crystal momentum but carry the same flux-dependent current, and the essential role of the interference between the collective components of the ground-state wave function. Calculation of the dynamic form factor reveals the presence of an acoustic mode that guarantees superfluidity in the
thermodynamic limit. The level statistics of the effective Hamiltonian is also discussed.

G. Pieplow, F. Sols, C.E. Creffield, "Generation of atypical hopping and
interactions by kinetic driving", New J. Phys. 20, 073045 (2018).
G. Pieplow, C.E. Creffield, F. Sols, "Protected cat states from kinetic
driving of a boson gas", Phys. Rev. Res. 1, 033013 (2019).
J. Mateos, C.E. Creffield, F. Sols, "Superfluidity from correlations in
driven boson systems", New J. Phys. 25, 063006 (2023).
J. Mateos, F. Sols, C.E. Creffield, "Floquet engineering spectral statistics
in the Bose-Hubbard model", arXiv:2306.09785v1 (2023).

Speaker: Fernando Sols (Universidad Complutense de Madrid)