Ordering dynamics of the driven lattice-gas model - art. no. 026105

The evolution of a two-dimensional driven lattice-gas model is studied on a n L(x)xL(y) lattice. Scaling arguments and extensive numerical simulations are used to show that starting from random initial configuration the model evolves via two stages: (a) an early stage in which alternating stripes of particles and vacancies are formed along the direction y of the driving fie ld, and (b) a stripe coarsening stage, in which the number of stripes is re duced and their average width increases. The number of stripes formed at th e end of the first stage is shown to be a function of L-x/L-y(phi), with ph i similar or equal to0.2. Thus, depending on this parameter, the resulting state could be either single or multistriped. In the second, stripe coarsen ing stage, the coarsening time is found to be proportional to L-y, becoming infinitely long in the thermodynamic limit. This implies that the multistr iped state is thermodynamically stable. The results put previous studies of the model in a more general framework.