Universal Quench Dynamics of an Open Quantum System

TL;DR

This paper investigates the universal dynamical behaviors of an open quantum system, specifically the quantum Kitaev chain, under environmental temperature quenches, revealing distinct scaling laws and universal behaviors related to quantum criticality.

Contribution

It introduces a comprehensive analysis of quench dynamics at quantum critical points, highlighting universal scaling laws and a new perspective on quantum criticality at finite temperatures.

Findings

Universal scaling laws at quantum critical points

Distinct exponents for zero and non-zero temperature quenches

Universal dynamical behavior independent of quantum criticality at finite temperatures

Abstract

Taking the quantum Kitaev chain as an example, we have studied the universal dynamical behaviors resulting from quantum criticality under the condition of environmental temperature quench. Our findings reveal that when the quantum parameter is at its critical value, both the excess excitation density at the end of linear quench and the subsequent free relaxation behavior exhibit universal scaling behaviors. The scaling laws observed upon quenching to the zero-temperature quantum critical point and non-zero temperature points exhibit distinct scaling exponents, which are all intimately related to the dynamical critical exponents of the quantum phase transition. Additionally, for the case of linear quench to finite temperatures, we have also discovered an intrinsic universal dynamical behavior that is independent of quantum criticality. Our research offers profound insights into the relationship between quantum criticality and nonequilibrium dynamics from two perspectives: Kibble-Zurek-like scaling behavior and free relaxation dynamics. Notably, the Kibble-Zurek-like scaling behavior in this context differs from the standard Kibble-Zurek mechanism. These two aspects jointly open up a new avenue for us to understand quantum criticality through real-time dynamical behavior, even at finite temperatures.