Coarsening dynamics in a simplified DNLS model

TL;DR

This paper studies the coarsening process in a simplified stochastic DNLS model at negative temperatures, explaining the observed coarsening exponent through an analogy with exclusion processes, highlighting its unique conservation laws.

Contribution

It introduces a simplified stochastic DNLS model and explains its coarsening exponent using an analogy with exclusion processes, despite its distinct conservation laws.

Findings

Coarsening exponent n=1/3 explained

Model exhibits unique dynamics with two conservation laws

Analogy with exclusion process elucidates behavior

Abstract

We investigate the coarsening evolution occurring in a simplified stochastic model of the Discrete NonLinear Schr\"odinger (DNLS) equation in the so-called negative-temperature region. We provide an explanation of the coarsening exponent $n=1/3$, by invoking an analogy with a suitable exclusion process. In spite of the equivalence with the exponent observed in other known universality classes, this model is certainly different, in that it refers to a dynamics with two conservation laws.