Department of Physics, Indian Institute of Technology Ropar, Rupnagar, Punjab 140001, India.
Phys Rev E. 2023 May;107(5-1):054110. doi: 10.1103/PhysRevE.107.054110.
We have studied the performance of a measurement-based quantum Otto engine (QOE) in a working system of two spins coupled by Heisenberg anisotropic interaction. A nonselective quantum measurement fuels the engine. We have calculated thermodynamic quantities of the cycle in terms of the transition probabilities between the instantaneous energy eigenstates, and also between the instantaneous energy eigenstates and the basis states of the measurement, when the unitary stages of the cycle operate for a finite time τ. The efficiency attains a large value in the limit of τ→0 and then gradually reaches the adiabatic value in a long-time limit τ→∞. For finite values of τ and for anisotropic interaction, an oscillatory behavior of the efficiency of the engine is observed. This oscillation can be interpreted in terms of interference between the relevant transition amplitudes in the unitary stages of the engine cycle. Therefore, for a suitable choice of timing of the unitary processes in the short time regime, the engine can have a higher work output and less heat absorption, such that it works more efficiently than a quasistatic engine. In the case of an always-on heat bath, in a very short time, the bath has a negligible effect on its performance.
我们研究了基于测量的量子奥托发动机（QOE）在由海森堡各向异性相互作用耦合的两个自旋工作系统中的性能。非选择性量子测量为发动机提供燃料。我们根据瞬时能量本征态之间的跃迁概率以及瞬时能量本征态与测量基态之间的跃迁概率来计算循环的热力学量，当循环的幺正阶段在有限时间 τ 内运行时。效率在 τ→0 的极限下达到很大的值，然后在 τ→∞ 的长时间极限下逐渐达到绝热值。对于有限的 τ 和各向异性相互作用，观察到发动机效率的振荡行为。这种振荡可以用发动机循环的幺正阶段中的相关跃迁振幅之间的干涉来解释。因此，对于短时间内的单位过程的适当定时选择，发动机可以具有更高的功输出和更少的热吸收，从而比准静态发动机更有效。在始终处于开启状态的热浴的情况下，在很短的时间内，浴对其性能的影响可以忽略不计。
