Long-Range Order in a Quasi One-Dimensional Non-Equilibrium Three-State Lattice Gas

Biased diffusion of two species with conserved dynamics on a 2xL periodic lattice is studied via Monte Carlo simulations. In contrast to its simple one-dimensional version on a ring, this quasi one-dimensional model surprisingly exhibits phase separation in its steady state, which is characterized by one macroscopic particle cluster. We study the order parameter and the cluster-size distributions as a function of the system size L, to support the above picture.