Revealing the work cost of generalized thermal baths

TL;DR

This paper derives the work cost of generalized thermal baths using quantum mechanics principles, demonstrating that only half of the invested work becomes useful, with the rest dissipated as heat, thus advancing understanding of quantum thermodynamics.

Contribution

It introduces a method to calculate work costs of generalized thermal baths based on quantum mechanics, linking quantum resources to classical thermodynamics.

Findings

Only half of the work invested is converted into useful output.

The remaining work is dissipated as heat.

The method provides a new tool for studying quantum thermodynamic resources.

Abstract

We derive the work cost of using generalized thermal baths from the physical equivalence of quantum mechanics under unitary transformations. We demonstrate our method by considering a qubit extracting work from a single bath to amplify a cavity field. There, we find that only half of the work investment is converted into useful output, the rest being wasted as heat. These findings establish the method as a promising tool for studying quantum resources within the framework of classical thermodynamics.