Nonequilibrium gas-liquid transition in the driven-dissipative photonic lattice

TL;DR

This paper investigates the nonequilibrium phase transition in a driven-dissipative photonic lattice, revealing a gas-liquid bistability phenomenon and formulating a van der Waals-like phase diagram for the system.

Contribution

It introduces a novel nonequilibrium gas-liquid phase transition framework for the driven-dissipative Bose-Hubbard model with Kerr nonlinearity, including phase diagrams and microscopic insights.

Findings

Identification of gas-liquid bistability at large cavity coupling J

Development of a van der Waals-like phenomenology for nonequilibrium transitions

Discovery of a lobe-shaped boundary separating smooth and hysteretic transitions

Abstract

We study the nonequilibrium steady state of the driven-dissipative Bose-Hubbard model with Kerr nonlinearity. Employing a mean-field decoupling for the intercavity hopping $J$, we find that the steep crossover between low and high photon-density states inherited from the single cavity transforms into a gas$-$liquid bistability at large cavity-coupling $J$. We formulate a van der Waals like gas$-$liquid phenomenology for this nonequilibrium situation and determine the relevant phase diagrams, including a new type of diagram where a lobe-shaped boundary separates smooth crossovers from sharp, hysteretic transitions. Calculating quantum trajectories for a one-dimensional system, we provide insights into the microscopic origin of the bistability.