Enhanced performance of sudden-quench quantum Otto cycles via multi-parameter control

TL;DR

This paper demonstrates that multi-parameter control in quantum Otto cycles enhances their efficiency and work output compared to single-parameter cycles, with applications to many-body quantum systems.

Contribution

It introduces a universal multi-parameter quench protocol for quantum thermodynamic cycles, showing improved performance in realistic many-body quantum systems.

Findings

Multi-parameter Otto cycles outperform single-parameter cycles in work and efficiency.

The protocol applies to systems like Bose gases and Ising models.

Enhanced coefficient of performance in refrigeration mode.

Abstract

Advances in experimental control of interacting quantum many-body systems with multiple tunable parameters-such as ultracold atomic gases and trapped ions-are driving rapid progress in quantum thermodynamics and enabling the design of quantum thermal machines. In this work, we utilize a sudden quench approximation as a means to investigate the operation of a quantum thermodynamic Otto cycle in which multiple parameters are simultaneously controllable. The method applies universally to many-body systems where such control is available, and therefore provides general principles for investigating their operation as a working medium in quantum thermal machines. We investigate application of this multi-parameter quench protocol in an experimentally realistic one-dimensional Bose gas, as well as in the transverse-field Ising model. We find that such a multi-parameter Otto cycle, when operating as an engine, outperforms not only its constituent single-parameter Otto cycles in terms of the net work and efficiency, but also the combined net work of its constituent engine cycles when added together independently. We also find that a similar multi-parameter enhancement applies to the coefficient of performance when the Otto cycle operates as a refrigerator.