Congestion fronts of diffusing particles

TL;DR

This paper introduces two models of particles invading a surface from opposite sides, analyzing how congestion fronts form and behave, revealing phase transitions and different roughness properties.

Contribution

The study presents two new models of particle invasion with reversible and irreversible congestion front formation, analyzing their self-affinity and phase transition behavior.

Findings

Congestion fronts are self-affine with distinct roughness exponents.

A phase transition exists between free movement and congestion at low densities.

Reversible and irreversible models exhibit different congestion dynamics.

Abstract

We study two new models of two particle species invading a surface from opposite sides. Collisions of particles of different species lead to the formation of congestion fronts. One of the models implements a reversible process whereas in the other model the congestion front forms irreversibly. For both models we find that the congestion fronts are self-affine but with different roughness exponents. For low densities the system does not congest and we find a phase transition between a phase of freely moving particles and a congestion phase.