Phase transition and phase coexistence in coupled rings with driven exclusion process

TL;DR

This paper investigates phase transitions and coexistence in coupled ring exclusion processes with diffusive and driven channels, revealing localized and delocalized domain walls influenced by current splitting.

Contribution

It introduces a model of coupled rings with diffusive and driven channels exhibiting bulk-driven phase transitions and domain wall dynamics, including a delocalization transition controlled by current splitting.

Findings

Bulk-driven phase transition observed in the model.

Localized domain wall formation in active channels.

Delocalization transition with delocalized domain walls.

Abstract

We study one-dimensional exclusion processes in two coupled closed rings consisting of a common diffusive channel and two parallel active (driven) channels. Our model displays bulk-driven phase transition and phase coexistence in the form of a localised domain wall (DW) in one of the active channels in a limit where the diffusive and driven dynamics compete. By controlling a splitting parameter which tunes the in-coming currents into the active channels, the system can be brought to a delocalisation transition, when delocalised DWs are formed in both the active channels. We characterise the DW fluctuations numerically.