Related papers: Enhancing the performance of coupled quantum Otto thermal machines without entanglement and quantum correlations

Enhancing the performance of coupled quantum Otto thermal machines without entanglement and quantum correlations

URL: http://arxiv.org/abs/2205.09725v1
Date: Thu, 19 May 2022 17:36:34 GMT
Title: Enhancing the performance of coupled quantum Otto thermal machines without entanglement and quantum correlations
Authors: Abdelkader El Makouri, Abdallah Slaoui, and Mohammed Daoud
Abstract summary: Two- and three-coupled spin-$1/2$ Heisenberg $XXX$-chain. We show that only when the number of interacting spins is odd the system can work as a heat engine in the strong coupling regime. This model confirms the idea that entanglement and quantum correlations are not the reasons behind the advantages observed in efficiency, extracatable work, and COP.
Score: 0.0
License: http://creativecommons.org/publicdomain/zero/1.0/
Abstract: We start with a revision study of two coupled spin-$1/2$ under the influence of KSEA interaction and a magnetic field. We first show the role of idel levels, i.e., levels that do not couple to the external magnetic field, when the system is working as a heat engine as well as when it is a refrigerator. Then we point out a flaw in [Phys. Rev. E. 92 (2015) 022142] by showing that it is not necessary to change both the magnetic field as well as the coupling parameters to break the extensive property of the work extracted globally from two coupled spin-$1/2$ as has been demonstrated there. Then we study the role of increasing the number of coupled spins on efficiency, extractable work, and coefficient of performance (COP). First, we consider two- and three-coupled spin-$1/2$ Heisenberg $XXX$-chain. We prove that the latter can outperform the former in terms of efficiency, extractable work, and COP. Then we consider the Ising model, where the number of interacting spins ranges from two to six. We show that only when the number of interacting spins is odd the system can work as a heat engine in the strong coupling regime. The enhancements in efficiency and COP are explored in detail. Finally, this model confirms the idea that entanglement and quantum correlations are not the reasons behind the advantages observed in efficiency, extracatable work, and COP, but only due to the structure of the energy levels of the Hamiltonian of the working substance.

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