论文标题
由时间翻译对称性驱动的非平衡多体量子发动机
Nonequilibrium many-body quantum engine driven by time-translation symmetry breaking
论文作者
论文摘要
以平衡的量子多体系统可以容纳有趣的现象，例如向异国动力学状态的过渡。尽管可以在实验中观察到这种紧急行为，但其技术应用的潜力在很大程度上没有探索。在这里，我们研究了集体效应对从多体系统提取机械工作的量子发动机的影响。通过使用相互作用的原子气体作为工作流体，我们使用光学机械腔设置，从理论上讲，这种引擎在周期性驾驶下产生了工作。工作流体的固定周期具有非平衡相变的，导致工作输出的突然变化。值得注意的是，我们发现我们的多体量子发动机即使没有定期驾驶也可以运行。当这种现象的工作流体进入打破连续的时间翻译对称的相位时，就会发生这种现象：新兴的时晶相可以维持负载产生机械工作的运动。我们的发现为设计新型非平衡量子机的设计铺平了道路。
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 opto-mechanical 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.
