https://doi.org/10.1140/epjp/s13360-025-06479-7
Regular Article
Optimal performance of a two-level quantum heat engine under the influence of an external magnetic field
Department of Physics, Wolkite University, Wolkite, Ethiopia
Received:
4
March
2025
Accepted:
24
May
2025
Published online:
12
June
2025
In this paper, we consider a finite-time quantum heat engine analogous to a finite-time classical Carnot heat engine with a working substance of spin-half particles. We conduct both analytical and numerical investigations of the optimized efficiency at two distinct optimal operating points, which lie between the maximum and minimum efficiencies of a quantum heat engine employing spin-half particles as the working substance under the influence of an external magnetic field. The efficiency of this engine under two optimal operating conditions exhibits anomalous behavior in specific regions of particle population levels. Moreover, we find that the efficiency in both cases surpasses all previously known bounds and even approaches the Carnot limit at finite times. To assess the overall performance of quantum heat engines, we introduce a figure of merit. Based on the proposed figure of merit, the model reveals that the second optimization criterion outperforms the first by a factor of three as a function of Carnot efficiency. Our findings highlight the pivotal role played by the population of spin-half particles in quantum heat engines, where their collective behavior in the quantum regime significantly enhances engine performance and efficiency.
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© The Author(s), under exclusive licence to Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2025
Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
