Theory of single-electron heat engines coupled to electromagnetic environments

TL;DR

This paper introduces a new class of mesoscopic heat engines where electrons transport work against a voltage bias while heat is transferred via microwave photons, enabling efficient energy conversion with diverse systems.

Contribution

It presents a generic formalism for mesoscopic heat engines coupled to electromagnetic environments and identifies conditions for maximal efficiency and power in various systems.

Findings

High efficiencies achievable with quantum dot arrays

High power output possible with metallic systems

Formalism applicable to various junctions and environments

Abstract

We introduce a new class of mesoscopic heat engines consisting of a tunnel junction coupled to a linear thermal bath. Work is produced by transporting electrons up against a voltage bias like in ordinary thermoelectrics but heat is transferred by microwave photons, allowing the heat bath to be widely separated from the electron system. A simple and generic formalism capable of treating a variety of different types of junctions and environments is presented. We identify the systems and conditions required for maximal efficiency and maximal power. High efficiencies are possible with quantum dot arrays but high power can also be achieved with metallic systems.