Condensation Transitions in Two Species Zero-Range Process

TL;DR

This paper analyzes condensation transitions in a two-species zero-range process, revealing new mechanisms of condensate formation, including a phase with inter-species support and defect-induced Bose-Einstein condensation.

Contribution

It provides an exact solution for the steady state and phase diagram of a two-species zero-range process, uncovering novel condensation phenomena and mechanisms.

Findings

Identification of a new phase with inter-species condensate support

Demonstration of defect particles inducing Bose-Einstein condensation

Exact phase diagram for a broad class of dynamics

Abstract

We study condensation transitions in the steady state of a zero-range process with two species of particles. The steady state is exactly soluble -- it is given by a factorised form provided the dynamics satisfy certain constraints -- and we exploit this to derive the phase diagram for a quite general choice of dynamics. This phase diagram contains a variety of new mechanisms of condensate formation, and a novel phase in which the condensate of one of the particle species is sustained by a `weak' condensate of particles of the other species. We also demonstrate how a single particle of one of the species (which plays the role of a defect particle) can induce Bose-Einstein condensation above a critical density of particles of the other species.