Stochastic thermodynamics under coarse-graining

TL;DR

This paper develops a framework for stochastic thermodynamics at the macrostate level, accounting for non-equilibrium microstates and their impact on entropy, with applications to quantum dot systems.

Contribution

It introduces a coarse-grained thermodynamic formulation that captures non-equilibrium microstates and their effects on entropy, extending traditional microscopic theories.

Findings

Macrostate thermodynamics derived from microstates

Non-equilibrium microstates contribute additional entropy terms

Application to coupled quantum dots demonstrates the theory

Abstract

A general formulation of stochastic thermodynamics is presented for open systems exchanging energy and particles with multiple reservoirs. By introducing a partition in terms of "macrostates" (e.g. sets of "microstates"), the consequence on the thermodynamic description of the system is studied in detail. When microstates within macrostates rapidly thermalize, the entire structure of the microscopic theory is recovered at the macrostate level. This is not the case when these microstates remain out of equilibrium leading to additional contributions to the entropy balance. Some of our results are illustrated for a model of two coupled quantum dots.