An exactly solvable relativistic quantum Otto engine

TL;DR

This paper constructs a relativistic quantum Otto engine using exactly solvable models, revealing how relativistic motion can both degrade and enhance work extraction depending on bath conditions, with potential experimental implications.

Contribution

It introduces a novel relativistic quantum Otto engine model based on solvable Unruh-DeWitt detectors, highlighting non-monotonic effects of speed on work output.

Findings

Relativistic motion affects work extraction differently for hot and cold baths.

Non-monotonic relationship between speed and work output observed.

Potential for experimental exploitation of relativistic effects in quantum thermodynamics.

Abstract

We revisit the mathematics of exactly solvable Unruh-DeWitt detector models, interacting with massless scalar fields under instantaneous interactions, to construct a relativistic quantum Otto heat engine. By deriving the conditions under which the thermodynamic cycle is closed we study the effects of motion on the amount of work that can be extracted from the machine when the working medium is moving at a constant relativistic velocity through the heat baths. While there is a degrading effect with respect to speed in the hot bath, we demonstrate that in the case of the cold bath, genuine enhancing effects are sometimes present. For couplings the same order as the inverse frequency of the detector and a specific value for the temporal separation between the two instantaneous interactions--needed in order to be possible to cool the detector--a non-monotonic dependence between speed and extracted work exists raising the intriguing possibility of exploiting relativistic effects for the enhancement of thermodynamic processes in tabletop experiments.