Nonequilibrium Many-Body Quantum Engine Driven by Time-Translation Symmetry Breaking
Nonequilibrium Many-Body Quantum Engine Driven by Time-Translation Symmetry Breaking
复制标题
时间平移对称性破缺驱动的非平衡多体量子引擎
DOI：
10.1103/physrevlett.125.240602
复制
发表时间：
2020
影响因子：
8.6
通讯作者：
Carollo F
中科院分区：
文献类型：
--
作者：
Carollo F
失去平衡的量子多体系统可以产生有趣的现象，例如向奇异动力学状态的转变。虽然这种涌现的行为可以在实验中观察到，但其技术应用的潜力在很大程度上尚未开发。在这里，我们研究了集体效应对从多体系统中提取机械功的量子引擎的影响。使用光机械腔装置与相互作用的原子气体作为工作流体，我们从理论上证明，这种发动机产生的工作下，周期性的驱动。工质的稳态循环具有非平衡相变的特征，导致输出功的突变。值得注意的是，我们发现我们的多体量子引擎甚至在没有周期性驱动的情况下也能运行。当它的工作流体进入一个打破连续时间平移对称性的相时，就会发生这种现象：出现的时间结晶相可以维持产生机械功的负载的运动。我们的发现为设计新型非平衡量子机器铺平了道路。
Quantum many-body systems out of equilibrium can host intriguing phenomena such as transitions to exotic dynamical states. Although this emergent behaviour can be observed in experiments, its potential for technological applications is largely unexplored. Here, we investigate the impact of collective effects on quantum engines that extract mechanical work from a many-body system. Using an optomechanical cavity setup with an interacting atomic gas as a working fluid, we demonstrate theoretically that such engines produce work under periodic driving. The stationary cycle of the working fluid features nonequilibrium phase transitions, resulting in abrupt changes of the work output. Remarkably, we find that our many-body quantum engine operates even without periodic driving. This phenomenon occurs when its working fluid enters a phase that breaks continuous time-translation symmetry: The emergent time-crystalline phase can sustain the motion of a load generating mechanical work. Our findings pave the way for designing novel nonequilibrium quantum machines.