Absorbing Phase Transitions in Variants of Lattice Gas Models with a Conserved Field

The critical behavior of absorbing phase transitions for two variant models with a conserved field were investigated. In the first, a disordered stochastic sandpile model was studied. In that model, each lattice site was occupied by up to 2d particles on a d-dimensional cubic lattice, and sites with 2d particles were considered to be active; otherwise, they were considered to be inactive. The disordered sites of the concentration q are added in the system, and particles on each disordered active site are assumed to hop deterministically, allowing only one particle in each direction. In the second, the conserved lattice gas (CLG) model was modified in a way that particles with two or more particles on the neighboring sites were considered active. We found that the disorder concentration of the first model was irrelevant, i.e., the critical behavior was found to be similar to that of the pure stochastic sandpile model, provided that q < 1. In the second, we found strong evidence that the variation of the rule of active particles in the CLG model yielded a critical behavior different from that of the ordinary CLG model.