Nonequilibrium free energy and information flow of a double quantum-dot system with Coulomb coupling

TL;DR

This paper investigates the thermodynamics and information flow in a Coulomb-coupled double quantum-dot system, revealing how energy and information contribute to irreversibility and enabling Maxwell Demon-like behavior.

Contribution

It introduces a stochastic thermodynamics framework combined with graph theory to analyze entropy, free energy, and information flow in quantum-dot systems, highlighting the role of feedback-induced information flow.

Findings

Thermodynamic irreversibility has energy and information contributions.

A global cycle can pump electrons against bias via feedback-induced information flow.

The study connects entropy production with information flow in quantum thermodynamics.

Abstract

We build a double quantum-dot system with Coulomb coupling and aim at studying the connections among the entropy production, free energy, and information flow. By utilizing the concepts in stochastic thermodynamics and graph theory analysis, the Clausius and nonequilibrium free energy inequalities are built to interpret the local second law of thermodynamics for subsystems. A fundamental set of cycle fluxes and affinities is identified to decompose the two inequalities by using Schnakenberg's network theory. The results show that the thermodynamic irreversibility has the energy-related and information-related contributions. A global cycle associated with the feedback-induced information flow would pump electrons against the bias voltage, which implements a Maxwell Demon.