Thermalization and prethermalization in isolated quantum systems: a theoretical overview

TL;DR

This paper reviews the theoretical understanding of how isolated quantum systems reach thermal equilibrium and exhibit prethermalization, emphasizing recent advances and experimental relevance in ultracold quantum gases.

Contribution

It provides a comprehensive overview of theoretical approaches to thermalization and prethermalization in isolated quantum systems, highlighting recent progress and physical insights.

Findings

Thermalization in quantum systems involves entanglement-driven features.

Prethermalization occurs with distinct time scales and various physical origins.

Ultracold gases serve as ideal experimental platforms for studying these phenomena.

Abstract

The approach to thermal equilibrium, or thermalization, in isolated quantum systems is among the most fundamental problems in statistical physics. Recent theoretical studies have revealed that thermalization in isolated quantum systems has several remarkable features, which emerge from quantum entanglement and are quite distinct from those in classical systems. Experimentally, well isolated and highly controllable ultracold quantum gases offer an ideal system to study the nonequilibrium dynamics in isolated quantum systems, triggering intensive recent theoretical endeavors on this fundamental subject. Besides thermalization, many isolated quantum systems show intriguing behavior in relaxation processes, especially prethermalization. Prethermalization occurs when there is a clear separation in relevant time scales and has several different physical origins depending on individual systems. In this review, we overview theoretical approaches to the problems of thermalization and prethermalization.