Study of the critical behavior of the driven lattice gas model with limited nonequilibrium dynamics

Abstract

Abstract In this paper the nonequilibrium critical behavior is investigated using a variant of the well-known two-dimensional driven lattice gas (DLG) model, called modified driven lattice gas (MDLG). In this model, the application of the external field is regulated by a parameter p ϵ [ 0 , 1 ] in such a way that if p = 0 , the field is not applied, and it becomes the Ising model, while if p = 1 , the DLG model is recovered. The behavior of the model is investigated for several values of p by studying the dynamic evolution of the system within the short-time regime in the neighborhood of a phase transition. It is found that the system experiences second-order phase transitions in all the interval of p for the density of particles ρ = 0.5 . The determined critical temperatures T c ( p ) are greater than the critical temperature of the Ising model T c I , and increase with p up to the critical temperature of the DLG model in the limit of infinite driving fields. The dependence of T c ( p ) on p is compatible with a power-law behavior whose exponent is ψ = 0.27 ( 3 ) . Furthermore, the complete set of the critical and the anisotropic exponents is estimated. For the smallest value of p , the ​dynamics and β exponents are close to that calculated for the Ising model, and the anisotropic exponent Δ is near zero. As p is increased, the exponents and Δ change, meaning that the anisotropy effects increase. For the largest value investigated, the set of exponents approaches to that reported by the most recent theoretical framework developed for the DLG model.