Entropy production and non-Gaussianity of fast processes at weak damping

TL;DR

This paper introduces a method to estimate entropy production in underdamped systems by decomposing it into contributions from various non-equilibrium effects, using experimental data from levitated nano-particles.

Contribution

It provides a novel approach to quantify entropy production by separating contributions from different non-equilibrium effects in underdamped dynamics.

Findings

Majority of entropy production attributed to velocity and position correlations

Estimates based on first and second moments are effective

Method applicable to experimental trajectory data

Abstract

We present a method of estimating the rate of entropy production in underdamped dynamics by decomposing it into contributions originating in different non-equilibrium effects. Specifically, a non-zero average velocity, a non-thermal width of the velocity distribution, correlations between position and velocity and non-Gaussian velocity statistics represent different ways in which the system can be out of equilibrium and each give rise to a positive contribution to the overall entropy production rate. We demonstrate that each contribution can be separately estimated from experimental trajectory data of levitated nano-particles subject to non-linear forces. We find that the majority of the entropy production rate can be attributed to the first three contributions which can be estimated from the first and second moments of the position and velocity and therefore result in a useful \enquote{Gaussian} estimate for the entropy production rate.