Thermalization and dissipation in out of equilibrium quantum systems: A perturbative renormalization group approach

TL;DR

This paper uses a perturbative renormalization group method to analyze how a periodic potential affects one-dimensional bosons in a non-equilibrium steady state, revealing new features like effective temperature and dissipation.

Contribution

It introduces a modified RG approach for non-equilibrium quantum systems, uncovering new phenomena such as temperature generation and altered quantum critical points.

Findings

Generation of an effective temperature in the system

Emergence of dissipation and friction effects

Shift in the quantum critical point location

Abstract

A perturbative renormalization group approach is employed to study the effect of a periodic potential on a system of one-dimensional bosons in a non-equilibrium steady-state due to an initial interaction quench. The renormalization group flows are modified significantly from the well known equilibrium Berezinski-Kosterlitz-Thouless form. They show several new features such as, a generation of an effective temperature, generation of dissipation, as well as a change in the location of the quantum critical point separating the weak coupling and strong coupling phases. Detailed results on the weak-coupling side of the phase diagram are presented, such as the renormalization of the parameters and the asymptotic behavior of the correlation functions. The physical origin of the generated temperature and friction is discussed.