Condensation transition and drifting condensates in the accelerated exclusion process

TL;DR

This paper investigates the dynamics of condensates in the accelerated exclusion process, revealing a phase diagram and showing that condensates drift with a velocity that diminishes in large systems, supported by mean-field analysis and simulations.

Contribution

It introduces a mean-field framework for the accelerated exclusion process and characterizes the phase diagram and condensate drift behavior.

Findings

Condensates drift with a velocity that vanishes in the thermodynamic limit.

The phase diagram of the AEP is mapped out using mean-field theory.

Numerical simulations support the theoretical predictions.

Abstract

Recently, it was shown that spatial correlations may have a drastic effect on the dynamics of real-space condensates in driven mass-transport systems: in models with a spatially correlated steady state, the condensate is quite generically found to drift with a non-vanishing velocity. Here we examine the condensate dynamics in the accelerate exclusion process (AEP), where spatial correlations are present. This model is a "facilitated" generalization of the totally asymmetric simple exclusion process (TASEP) where each hopping particle may trigger another hopping event. Within a mean-field approach that captures some of the effects of correlations, we calculate the phase diagram of the AEP, analyze the nature of the condensation transition, and show that the condensate drifts, albeit with a velocity that vanishes in the thermodynamic limit. Numerical simulations are consistent with the mean-field phase diagram.