Séminaire du LPTMS: Marco Schirò

Defying Quantum Thermalization through Interactions and Disorder: From Many Body Localization to Quantum Glassiness

Marco Schirò (IPHT and Collège de France)

Generic interacting quantum many body systems are expected to reach thermal equilibrium when isolated from their environment and let evolve under their own quantum dynamics. Exceptions to this paradigm can emerge in presence of quenched random disorder, due to many body localization (MBL) or quantum glassiness. Those two robust scenarios for ergodicity breaking have recently attracted considerable interest both from a purely theoretical viewpoint and for their implications on the robustness of future quantum technologies.
In this talk I will study the quantum dynamics of two prototype models for MBL and quantum glassy systems.
I will first introduce a theoretical framework based on flow equations to study the properties MBL systems, in particular the emergence of localised integral of motions, and their dynamics. Then I will consider a mean field model of a quantum glass and I will study its isolated dynamics after a quantum quench. I will show that, contrary to the conventional wisdom based on thermodynamics, quantum fluctuations and non equilibrium effects result in an enhanced glassiness and ageing behavior.

Date/Time : 24/09/2019 - 11:00 - 12:00

Location : Salle des séminaires du FAST et du LPTMS, bâtiment Pascal n°530