Chaos and Dynamics in Correlated Quantum Matter

Workshop Report

Chaos and Dynamics in Correlated Quantum Matter

Scientific Coordination

• David Luitz (Technische Universität München, Garching)
• Roderich Moessner (Max-Planck-Institut für Physik komplexer Systeme, Dresden)
• Frank Pollmann (Technische Universität München, Garching)

Organization

• Katrin Lantsch (Max-Planck-Institut für Physik komplexer Systeme, Dresden)

The international MPI-PKS workshop “Chaos and Dynamics in Correlated Quantum Matter” was held from 19 - 22 March 2018. The aim of the workshop was to bring together leading scientists working on the dynamics of quantum many body systems. The dynamics of complex systems is apparently irriversible, seemingly in contradiction with the intrinsic reversibility of the microscopic laws of nature. The effective formation of an arrow of time by complex dynamics is an ongoing debate lasting over more than a century. Chaos plays a crucial role in resolving this paradox, and the past decade has seen a great revival of interest in this question concerning the foundations of quantum statistical mechanics and how chaos arises in quantum many-body systems due to enormous computational, theoretical and experimental progress in the field. Important milestones are theoretical findings involving the long sought demonstration that many-body localization (MBL) exists as well as the derivation of exact bounds on chaos and the discovery of spontaneous time translation symmetry breaking. On the experimental side, significant advances have been made in the study of cold atomic gases which provide examples of closed macroscopic quantum systems for which the foundational questions of quantum statistical mechanics are particularly relevant:

• Operator spreading
• Out-of-time-order correlations
• Dynamic entanglement formation
• Quantum thermalization
• Novel quantum phases out of equilibrium
• Spatio-temporal orders
• Efficient numerical simulation of quantum many-body dynamics
• Many-body localization

The organizers attempted to have a wide representation of invited talks from different fields, including established as well as junior scientists: Operator spreading (Adam Nahum, Curt von Keyserlingk, Tibor Rakovszky and Vedika Khemani), Out-of-time-order correlations (Balazs Dora, Yevgeny Bar Lev, Michael Knap, Victor Galitski, Adam Green, Klaus Richter and Subhro Bhattacharjee), Many-body chaos and thermalization (Lea Ferreira dos Santos, Marcos Rigol, Alexey Gorshkov, Tomaz Prosen and Jorge Kurchan), Spatio-temporal orders (Shivaji Sondhi, Achilleas Lazarides, Sthitadhi Roy), Many-body localization (Thorsten Wahl, Janez Bonca and Adam Smith), Statistical Mechanics and high energy Physics (Peter Reimann, Hong Liu, Mukund Rangamani).

The talks were well attended and discussions to these topics were very lively. The longer lunch and coffee breaks were useful as they led to many stimulating discussions between the participants. In particular, the provided up to 6 discussion rooms were very well received and used for smaller group discussions which contributed to a collaborative atmosphere.

The poster sessions, which gave particularly young researchers the chance to present their results, were well attended and discussion in front of the posters lasted until late in the night.

Shivaji Sondhi (Princeton, USA) accepted our invitation as the distinct speaker of the institute's colloquium in which he gave a overview talk on “Statistical mechanics, localization and periodically driven quantum systems”. His very inspiring talk highlighted many of the recent theoretical advances in the understanding of driven quantum systems and attracted a very large audience.