Spontaneous Symmetry Breaking in Two-Channel Asymmetric Exclusion Processes with Narrow Entrances

TL;DR

This paper investigates the non-equilibrium dynamics of a two-channel asymmetric exclusion process with narrow entrances, revealing four stationary phases including spontaneous symmetry breaking, supported by mean-field analysis and Monte Carlo simulations.

Contribution

The study introduces a theoretical analysis of coupled two-channel exclusion processes with boundary interactions, identifying multiple phases and symmetry breaking phenomena not previously characterized.

Findings

Four stationary phases identified, two with spontaneous symmetry breaking.

Monte Carlo simulations support mean-field predictions qualitatively.

Phase boundaries and properties depend strongly on system size.

Abstract

Multi-particle non-equilibrium dynamics in two-channel asymmetric exclusion processes with narrow entrances is investigated theoretically. Particles move on two parallel lattices in opposite directions without changing them, while the channels are coupled only at the boundaries. A particle cannot enter the corresponding lane if the exit site of the other lane is occupied. Stationary phase diagrams, particle currents and densities are calculated in a mean-field approximation. It is shown that there are four stationary phases in the system, with two of them exhibiting spontaneous symmetry breaking phenomena. Extensive Monte Carlo computer simulations confirm qualitatively our predictions, although the phase boundaries and stationary properties deviate from the mean-field results. Computer simulations indicate that several dynamic and phase properties of the system have a strong size dependency, and one of the stationary phases predicted by the mean-field theory disappears in the thermodynamic limit.