Entropy production of active particles and for particles in active baths

TL;DR

This paper develops a thermodynamically consistent model to quantify entropy production in active particles, revealing unique contributions from active propulsion and diffusion, and extends the framework to interacting particles and active baths.

Contribution

It introduces a minimal lattice model for entropy production in active particles, providing a clear continuum limit expression and addressing ambiguities in Langevin-based calculations.

Findings

Derived a unique entropy production expression combining active and diffusive effects

Extended the model to multiple interacting active and passive particles

Highlighted limitations of conventional trajectory comparison methods

Abstract

Entropy production of an active particle in an external potential is identified through a thermodynamically consistent minimal lattice model that includes the chemical reaction providing the propulsion and ordinary translational noise. In the continuum limit, a unique expression follows, comprising a direct contribution from the active process and an indirect contribution from ordinary diffusive motion. From the corresponding Langevin equation, this physical entropy production cannot be inferred through the conventional, yet here ambiguous, comparison of forward and time-reversed trajectories. Generalizations to several interacting active particles and passive particles in a bath of active ones are presented explicitly, further ones are briefly indicated.