Phase transitions in the driven lattice gas (TASEP) with repulsive energies

We report on non-equilibrium phase transitions in the driven lattice gas model totally asymmetric exclusion processes caused by nearest-neighbor (NN) repulsions between particles, ɛ > 0, employing extensive Monte Carlo simulations and mean-field calculations. The diagra of phase regimes has five different regimes which are separated by distinct boundaries. We discuss the density of particles and the current which depend differently in the various regimes on the system’s entry and exit rates of particles, α and β , respectively. The steady state can be described by quasi-particles called ‘soft dimerons’, where each dimeron consists of a particle dragging an empty NN site on its left. The asymptotic state of dimerons at ε → ∞ is equivalent to the state of hard dimers at ɛ = 0. Since the model is a uni-directional fluid, it has an internal hydrodynamic pressure which increases with increasing inter-particle repulsion ɛ . This leads to a collective effect which causes phase transitions between high and low densities of particles at certain critical points ɛ c .