Bose-Einstein Condensation In Disordered Exclusion Models and Relation to Traffic Flow

TL;DR

This paper investigates a disordered asymmetric exclusion model exhibiting Bose-Einstein condensation phenomena, revealing phase transitions and velocity behavior, with implications for traffic flow modeling.

Contribution

It provides an exact solution for a disordered exclusion model showing Bose condensation and analyzes phase transitions and velocity exponents.

Findings

Bose condensation can occur in disordered exclusion models.

A phase transition from low to high density is identified.

Velocity decreases analytically depend on hopping rate distribution.

Abstract

A disordered version of the one dimensional asymmetric exclusion model where the particle hopping rates are quenched random variables is studied. The steady state is solved exactly by use of a matrix product. It is shown how the phenomenon of Bose condensation whereby a finite fraction of the empty sites are condensed in front of the slowest particle may occur. Above a critical density of particles a phase transition occurs out of the low density phase (Bose condensate) to a high density phase. An exponent describing the decrease of the steady state velocity as the density of particles goes above the critical value is calculated analytically and shown to depend on the distribution of hopping rates. The relation to traffic flow models is discussed.