Dynamical Critical Phenomena in Driven-Dissipative Systems

TL;DR

This paper investigates the critical behavior of driven open quantum systems, revealing a new universality class and critical exponent through a functional renormalization group approach, with implications for experiments on cold atoms and polaritons.

Contribution

It introduces a novel dynamical universality class and critical exponent for driven-dissipative systems, extending the understanding of phase transitions beyond equilibrium classifications.

Findings

Identification of a new dynamical universality class.

Discovery of a unique critical exponent for driven systems.

Proposals for experimental probing in cold atomic and polariton systems.

Abstract

We explore the nature of the Bose condensation transition in driven open quantum systems, such as exciton-polariton condensates. Using a functional renormalization group approach formulated in the Keldysh framework, we characterize the dynamical critical behavior that governs decoherence and an effective thermalization of the low frequency dynamics. We identify a critical exponent special to the driven system, showing that it defines a new dynamical universality class. Hence critical points in driven systems lie beyond the standard classification of equilibrium dynamical phase transitions. We show how the new critical exponent can be probed in experiments with driven cold atomic systems and exciton-polariton condensates.