Theory of Driven Nonequilibrium Critical Phenomena

TL;DR

This paper develops a universal dynamic renormalization-group theory describing nonequilibrium critical phenomena in driven systems near their critical points, revealing rich behaviors and crossovers influenced by driving and initial conditions.

Contribution

It introduces a comprehensive theoretical framework linking nonequilibrium critical behavior to equilibrium properties using dynamic renormalization-group methods.

Findings

Universal nonequilibrium critical behavior described by equilibrium properties

Multiple time scales and rich phenomena due to weak driving

Implications for measurement and broader nonlinear systems

Abstract

A system driven in the vicinity of its critical point by varying a relevant field in an arbitrary function of time is a generic system that possesses a long relaxation time compared with the driving time scale and thus represents a large class of nonequilibrium systems. For such a manifestly nonlinear nonequilibrium strongly fluctuating system, we show that there exists universal nonequilibrium critical behavior that is well described incredibly by its equilibrium critical properties. A dynamic renormalization-group theory is developed to account for the behavior. The weak driving may give rise to several time scales depending on its form and thus rich nonequilibrium phenomena of various regimes and their crossovers, negative susceptibilities, as well as violation of fluctuation-dissipation theorem. An initial condition that can be in either equilibrium or nonequilibrium but has longer correlations than the driving scales also results in a unique regime and complicates the situation. Implication of the results on measurement is also discussed. The theory may shed light on study of other nonequilibrium systems and even nonlinear science.