Inverse Current in Coupled Transport: A Quantum Thermodynamic Model

TL;DR

This paper develops a quantum thermodynamic model to explain the inverse current phenomenon in coupled transport, revealing conditions for its occurrence and potential applications in quantum engines and refrigerators.

Contribution

It introduces an exactly solvable quantum model and a thermodynamic framework to analyze inverse currents at the quantum level, linking microscopic and macroscopic entropy production.

Findings

Identifies conditions for genuine inverse current in quantum transport.

Connects microscopic entropic biases with macroscopic entropy production.

Suggests applications in autonomous quantum thermal devices.

Abstract

The recent discovery of inverse current in coupled transport (ICC) in classical systems~\textcolor{blue}{[\textbf{Phys. Rev. Lett.} \textbf{124}, 110607 (2020)]} -- where an induced current flows opposite to two mutually parallel thermodynamic forces, yet remains consistent with the second law of thermodynamics -- reveals a striking and counterintuitive transport phenomenon. Using an exactly solvable model of strongly coupled quantum dots, we develop a thermodynamic framework to describe the ICC phenomenon at the quantum level. By systematically connecting the microscopic and macroscopic formulations of the entropy production rate in terms of appropriate entropic biases and entropic fluxes, our analysis identifies the conditions under which a \textit{genuine} ICC effect can arise in quantum thermal transport and highlights potential applications in autonomous quantum engines and refrigerators.