Disorder Enhanced Thermalization in Interacting Many-Particle System

TL;DR

This paper extends non-equilibrium dynamical mean field theory to include static disorder effects, revealing that weak disorder can promote thermalization and alter quasiparticle dynamics in many-particle systems.

Contribution

It introduces a novel method to incorporate static disorder into non-equilibrium dynamical mean field theory, enabling analysis of disorder effects on system dynamics.

Findings

Weak disorder promotes thermalization.

Disorder suppresses quasiparticle weight jumps.

Disorder reduces amplitude of quasiparticle oscillations.

Abstract

We introduce an extension of the non-equilibrium dynamical mean field theory to incorporate the effects of static random disorder in the dynamics of a many-particle system by integrating out different disorder configurations resulting in an effective time-dependent density-density interaction. We use this method to study the non-equilibrium transient dynamics of a system described by the Fermi Anderson-Hubbard model following an interaction and disorder quench. The method recovers the solution of the disorder-free case for which the system exhibits qualitatively distinct dynamical behaviors in the weak-coupling (prethermalization) and strong-coupling regimes (collapse-and-revival oscillations). However, we find that weak random disorder promotes thermalization. In the weak coupling regime, the jump in the quasiparticle weight in the prethermal regime is suppressed by random disorder while in the strong-coupling regime, random disorder reduces the amplitude of the quasiparticle weight oscillations. These results highlight the importance of disorder in the dynamics of realistic many-particle systems.