Ordering dynamics of the driven lattice-gas model

The evolution of a two-dimensional driven lattice-gas model is studied on an 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 field, and (b) a stripe coarsening stage, in which the number of stripes is reduced and their average width increases. The number of stripes formed at the end of the first stage is shown to be a function of L-x/L-y(phi), with phi similar or equal to0.2. Thus, depending on this parameter, the resulting state could be either single or multistriped. In the second, stripe coarsening stage, the coarsening time is found to be proportional to L-y, becoming infinitely long in the thermodynamic limit. This implies that the multistriped state is thermodynamically stable. The results put previous studies of the model in a more general framework.