Stationary state in a two-temperature model with competing dynamics

TL;DR

This paper investigates a two-temperature lattice gas model with competing dynamics, revealing how interface stability and particle condensation depend on the temperature difference and probabilistic coupling to thermal baths.

Contribution

It introduces a novel two-temperature model with competing dynamics and analyzes its stationary states using Monte Carlo simulations and mean-field approximation.

Findings

Vertical and horizontal interfaces become unstable.

Interfaces are stable in diagonal directions.

Particles condense into a tilted square in the ordered state.

Abstract

A two-dimensional half-filled lattice gas model with nearest-neighbor attractive interaction is studied where particles are coupled to two thermal baths at different temperatures $T_1$ and $T_2$. The hopping of particles is governed by the heat bath at temperature $T_1$ with probability $p$ and the other heat bath $(T_2)$ with probability $1-p$ independently of the hopping direction. On a square lattice the vertical and horizontal interfaces become unstable while interfaces are stable in the diagonal directions. As a consequence, particles condense into a tilted square in the novel ordered state. The $p$-dependence of the resulting nonequilibrium stationary state is studied by Monte Carlo simulation and dynamical mean-field approximation as well.