Bath-induced Zeno localization in driven many-body quantum systems
Thibaud Maimbourg (LPTMS)
Online seminar — ZOOM Meeting ID: 979 6114 1696 — Password: 105367 —
In this talk I will first discuss the main conditions for a many-body quantum system to reach a thermal stationary state. I will then focus on the mechanism by which, relaxing one of these conditions, the system in contact with a bath of spatially-localized vibrational modes can fail to reach such a state. As a realistic illustration, I shall consider a quantum interacting spin system subject to an external drive, serving as a model for dynamic nuclear polarization (DNP) protocols. Those protocols, besides their concrete applications, represent an experimental platform to investigate ergodicity of the stationary state. Even when the isolated system is ergodic, a sufficiently strong coupling to the bath may break ergodicity, due to many-body quantum Zeno effect. In the DNP context, this result provides an explanation of the breakdown of the so-called « thermal mixing » regime (effective equilibrium), experimentally observed above 4 – 5 Kelvin.
Ref.: arXiv:2009.11784. Joint work with D. M. Basko, M. Holzmann (LPMMC Grenoble), A. Rosso (LPTMS).