Condensation and coexistence in a two-species driven model

TL;DR

This paper investigates how a two-species driven system with degenerate maxima in the current-density relation exhibits phase coexistence and enhanced phase separation, affecting steady state properties and particle distribution.

Contribution

It reveals the coexistence of phases in both fluid and condensate regions and introduces a selection mechanism for equal currents, impacting the system's steady state behavior.

Findings

Coexistence of two maximal current phases in fluid and condensate.

Enhanced phase separation compared to single maximum systems.

Neutral fluid with equal outflow currents despite particle imbalance.

Abstract

Condensation transition in two-species driven systems in a ring geometry is studied in the case where current-density relation of a domain of particles exhibits two degenerate maxima. It is found that the two maximal current phases coexist both in the fluctuating domains of the fluid and in the condensate, when it exists. This has a profound effect on the steady state properties of the model. In particular, phase separation becomes more favorable, as compared with the case of a single maximum in the current-density relation. Moreover, a selection mechanism imposes equal currents flowing out of the condensate, resulting in a neutral fluid even when the total number of particles of the two species are not equal. In this case the particle imbalance shows up only in the condensate.