Tuning universality far from equilibrium

TL;DR

This paper investigates universal behaviors in many-body systems far from equilibrium, focusing on meta-stable non-thermal states with critical properties, and demonstrates how tuning system parameters can induce dynamical phase transitions.

Contribution

It introduces the concept of tuning universality far from equilibrium to induce dynamical phase transitions in a superfluid Bose gas.

Findings

Identification of meta-stable non-thermal states with critical properties

Proposal of tuning parameters to induce dynamical phase transitions

Scaling exponents as indicators of different critical regimes

Abstract

Possible universal dynamics of a many-body system far from thermal equilibrium are explored. A focus is set on meta-stable non-thermal states exhibiting critical properties such as self-similarity and independence of the details of how the respective state has been reached. It is proposed that universal dynamics far from equilibrium can be tuned to exhibit a dynamical phase transition where these critical properties change qualitatively. This is demonstrated for the case of a superfluid two-component Bose gas exhibiting different types of long-lived but non-thermal critical order. Scaling exponents controlled by the ratio of experimentally tuneable coupling parameters offer themselves as natural smoking guns. The results shed light on the wealth of universal phenomena expected to exist in the far-from-equilibrium realm.