Effect of Thermal Noise on Conserved Lattice Gas

Abstract

We present a modified conserved lattice gas (CLG) model in two dimensions with a thermal noise parameter, P = exp(−1/T), where T is the effective temperature. In particular, we focus on the interplay of thermal noise P and the total density of particles ρ in the CLG model. The universality class of the case of 0 <P < 1 can be compared with P = 0 and P =1 cases. We discuss the critical behavior of absorbing phase transitions in the generalized CLG (GCLG) model by two well-defined order parameters: one is the density of active particles (a pair of consecutive particles) and the other is the density of energy-loss particles. While the former is useful at P = 1 (T = ∞)asthe typical one in nonequilibrium absorbing phase transitions, the latter is suggested as the best at P = 0 (T = 0) due to the oscillatory behavior in the localized active phase. Based on extensive numerical tests, we find that the density of energy-loss particles can also be a good indicator even for finite P values. Finally, we propose a schematic phase diagram of the GCLG as P varies.