Entropy production and fluctuation relations for a KPZ interface

TL;DR

This paper investigates entropy production and fluctuation relations in a microscopic KPZ interface model, revealing how entropy measures distance from equilibrium and exploring symmetry properties of height fluctuations.

Contribution

It provides an exact solution for a specific line in the phase diagram of the KPZ model, linking entropy production to non-equilibrium behavior and analyzing large deviation symmetries.

Findings

Entropy production quantifies the distance from equilibrium.

Large deviation function for height variation can be symmetric.

Different symmetry than Gallavotti-Cohen observed in a special case.

Abstract

We study entropy production and fluctuation relations in the restricted solid-on-solid growth model, which is a microscopic realization of the KPZ equation. Solving the one dimensional model exactly on a particular line of the phase diagram we demonstrate that entropy production quantifies the distance from equilibrium. Moreover, as an example of a physically relevant current different from the entropy, we study the symmetry of the large deviation function associated with the interface height. In a special case of a system of length L=4 we find that the probability distribution of the variation of height has a symmetric large deviation function, displaying a symmetry different from the Gallavotti-Cohen symmetry.