Condensation induced by coupled transport processes

TL;DR

This paper investigates how coupled transport processes in a lattice model with two conservation laws lead to condensation phenomena, especially under out-of-equilibrium conditions, revealing localization effects and the influence of boundary conditions.

Contribution

It introduces a lattice model with two conservation laws under open boundary conditions, analyzing condensation and localization phenomena in out-of-equilibrium states.

Findings

Condensation occurs in out-of-equilibrium conditions with internal localization.

Boundary conditions influence the presence or absence of condensates.

The number of conservation laws affects the condensation behavior.

Abstract

Several lattice models display a condensation transition in real space when the density of a suitable order parameter exceeds a critical value. We consider one of such models with two conservation laws, in a one-dimensional open setup where the system is attached to two external reservoirs. Both reservoirs impose subcritical boundary conditions at the chain ends. When such boundary conditions are equal, the system is in equilibrium below the condensation threshold and no condensate can appear. Instead, when the system is kept out of equilibrium, localization may arise in an internal portion of the lattice. We discuss the origin of this phenomenon, the relevance of the number of conservation laws, and the effect of the pinning of the condensate on the dynamics of the out-of-equilibrium state.