Stochastic Thermodynamics of a Particle in a Box

TL;DR

This paper develops a novel approach to apply stochastic thermodynamics to a particle in a box, deriving analytical work distributions and optimal protocols, thus bridging a significant gap in the field.

Contribution

It introduces a coordinate transformation technique enabling stochastic thermodynamics analysis of a particle in a box, previously hindered by potential singularities.

Findings

Derived analytical work distribution for arbitrary protocols.

Verified Fluctuation-Dissipation Relation predictions.

Identified optimal protocol for Brownian Szilard's engine.

Abstract

The piston system (particles in a box) is the simplest and paradigmatic model in traditional thermodynamics. However, the recently established framework of stochastic thermodynamics (ST) fails to apply to this model system due to the embedded singularity in the potential. In this Letter we study the stochastic thermodynamics of a particle in a box by adopting a novel coordinate transformation technique. Through comparing with the exact solution of a breathing harmonic oscillator, we obtain analytical results of work distribution for an arbitrary protocol in the linear response regime, and verify various predictions of the Fluctuation-Dissipation Relation. When applying to the Brownian Szilard's engine model, we obtain the optimal protocol $\lambda_t = \lambda_0 2^{t/\tau}$ for a given sufficiently long total time $\tau$. Our study not only establishes a paradigm for studying ST of a particle in a box, but also bridges the long-standing gap in the development of ST.