Particle redistribution and slow decay of correlations in hard-core fluids on a half-driven ladder

We study driven particle systems with excluded volume interactions on a two-lane ladder with periodic boundaries, using Monte Carlo simulation, cluster mean-field theory, and numerical solution of the master equation. Particles in one lane are subject to a drive that forbids motion along one direction, while in the other lane the motion is unbiased; particles may jump between lanes. Despite the symmetry of the rates for transitions between lanes, the associated particle densities are unequal: at low densities there is an excess of particles in the undriven lane, while at higher densities the tendency is reversed. Similar results are found for an off-lattice model. We quantify the reduction in the stationary entropy caused by the drive. The stationary two-point correlation functions are found to decay algebraically, both on- and off-lattice. In the latter case the exponent governing the decay varies continuously with the density.