Nonequilibrium phase transition by directed Potts particles

TL;DR

This paper investigates nonequilibrium phase transitions in a q-species interface model, revealing different universality classes for q=1, 2, and 3 or more, with connections to directed percolation, Ising, and Edwards-Wilkinson dynamics.

Contribution

It introduces a new interface model with q-fold symmetry to classify nonequilibrium phase transitions based on the number of species q.

Findings

For q=1, the transition is in the directed percolation class.

For q=2, the transition belongs to the directed Ising class.

For q≥3, the transition occurs at a finite critical probability p_c, independent of q.

Abstract

We introduce an interface model with q-fold symmetry to study the nonequilibrium phase transition (NPT) from an active to an inactive state at the bottom layer. In the model, q different species of particles are deposited or are evaporated according to a dynamic rule, which includes the interaction between neighboring particles within the same layer. The NPT is classified according to the number of species q. For q=1 and 2, the NPT is characterized by directed percolation, and the directed Ising class, respectively. For $q \ge 3$, the NPT occurs at finite critical probability p_c, and appears to be independent of q; the $q=\infty$ case is related to the Edwards-Wilkinson interface dynamics.