Thermodynamically consistent model of an active Ornstein-Uhlenbeck particle

TL;DR

This paper presents a thermodynamically consistent microscopic model of an active particle that accurately captures entropy production from both thermal and active sources, improving understanding of active matter thermodynamics.

Contribution

The paper introduces a minimal microscopic model for active particles that accounts for both thermal noise and active propulsion, enabling precise entropy production calculations.

Findings

The model reproduces active Ornstein-Uhlenbeck statistics in the continuum limit.

Traditional methods underestimate entropy production in active systems.

Microscopic Markovian models serve as benchmarks for entropy analysis.

Abstract

Identifying the full entropy production of active particles is a challenging task. We introduce a microscopic, thermodynamically consistent model, which leads to active Ornstein-Uhlenbeck statistics in the continuum limit. Our minimal model consists of a particle with a fluctuating number of active reaction sites which contribute to its active self-propulsion on a lattice. In addition, the model also takes ordinary thermal noise into account. This approach allows us to identify the full entropy production stemming from both thermal diffusion and active driving. Extant methods based on the comparison of forward and time-reversed trajectory underestimate the physical entropy production when applied to the Langevin equations obtained from our model. Constructing microscopic Markovian models can thus provide a benchmark for determining the entropy production in non-Markovian active systems.