NONEQUILIBRIUM PHASE TRANSITIONS IN A SIMPLE THREE-STATE LATTICE GAS

摘要

We investigate the dynamics of a three-state stochastic lattice gas consisting of holes and two oppositely ''charged'' species of particles, under the influence of an ''electric'' field at zero total charge. Interacting only through an excluded-volume constraint, particles exchange with holes and, on a slower time scale, with each other. Using a combination of Monte Carlo simulations and mean-field equations of motion, we study a set of suitably defined order parameters, their histograms and fluctuations, as well as the current through the system. With increasing particle density and drive, the system first orders into a charge-segregated state, and then disorders again near complete filling. The transition is first order at low densities and turns second order at higher ones. The finite-size and aspect-ratio dependence of characteristic quantities is discussed at the mean-field level. [References: 39]