论文标题
增强耦合量子奥托热机的性能，而无需纠缠和量子相关
Enhancing the performance of coupled quantum Otto thermal machines without entanglement and quantum correlations
论文作者
论文摘要
我们从在Kaplan-Shekhtman-Entin-Wohlman-Aharony（KSEA）相互作用和一个磁场的影响下对两个耦合自旋$ 1/2 $的修订研究开始。我们首先显示闲置水平的作用，即当系统作为热发动机以及冰箱时，当系统起作用时，没有将其与外部磁场相结合的水平。然后，我们扩展了[pre。 92，（2015）022142]通过证明不必更改磁场以及耦合参数，以破坏从两个耦合旋转$ 1/2 $中全球提取的广泛特性，如那里所证明的那样。然后，我们研究增加耦合旋转数量在效率，可提取工作和性能系数（COP）上的作用。首先，我们考虑两耦合旋转 - $ 1/2 $ HEISENBERG $ \ MATHRM {XXX} $ - 链。我们证明，在效率，可提取工作和COP方面，后者可以胜过前者。然后，我们考虑ISING模型，其中相互作用的旋转数量为两个到六个。我们表明，只有当相互作用的旋转数量奇怪时，系统才能在强耦合方面充当加热发动机。详细探讨了效率和COP的增强。最后，该模型证实了这样一个想法，即纠缠和量子相关不是在效率，可蓄积的工作和COP中观察到的增强的原因，而仅是由于工作物质的哈密顿量的能量水平的结构。除此之外，全球工作的广泛特性不受纠缠和量子相关性的影响。
We start with a revision study of two coupled spin-$1/2$ under the influence of Kaplan-Shekhtman-Entin-Wohlman-Aharony (KSEA) interaction and a magnetic field. We first show the role of idle 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 extend the results reported in [PRE. 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 $\mathrm{XXX}$-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 enhancements observed in efficiency, extracatable work, and COP, but only due to the structure of the energy levels of the Hamiltonian of the working substance. In addition to this, the extensive property of global work as well, is not affected by entanglement and quantum correlations.
