Relativistic quantum Otto engine driven by the circular Unruh effect

TL;DR

This paper introduces a relativistic quantum Otto engine model driven by the circular Unruh effect, analyzing a qubit's interaction with a quantum field during circular acceleration and its impact on work output and efficiency.

Contribution

It develops a novel relativistic quantum engine framework using circular acceleration and explores the effects of the Unruh effect on engine performance.

Findings

Work output increases with acceleration and approaches an asymptotic limit.

Response function of the qubit is significantly modified by circular trajectory.

Engine efficiency remains unaffected by circular motion.

Abstract

In this work, we present a new framework for a relativistic quantum analouge of the classical Otto engine. Considering a single qubit as the working substance, we analyse its interaction with a massless quantum scalar field while undergoing two half-circular rotations at ultra-relativistic velocities. The quantum vacuum serves as a thermal bath through the Unruh effect induced due to the acceleration from the circular motions. We observe that the response function of the qubit gets significantly modified by the presence of the qubit's trajectory. Analysing the transition probability behaviour, we find that in the high-acceleration regime, it asymptotically approaches a constant value, determined solely by the properties of the correlation function. Furthermore, our results emphasize the crucial role of the circular trajectory in determining the engine's work output. In particular, the extracted work increases with detector acceleration and approaches an asymptotic limit in the high-acceleration regime. Notably, the efficiency of this model remains unaffected by the circular motion and is consistent with previously studied models.