Non-stationary coherent quantum many-body dynamics through dissipation
Non-stationary coherent quantum many-body dynamics through dissipation
复制标题
DOI：
10.1038/s41467-019-09757-y
复制
发表时间：
2019-04-15
影响因子：
16.6
通讯作者：
Jaksch, Dieter
中科院分区：
文献类型：
--
作者：
Buca, Berislav;Tindall, Joseph;Jaksch, Dieter
量子系统在长时间内松弛到静止状态的假设，支撑了统计物理学和我们对科学现象的许多直观理解。对于孤立系统，这源于本征态热化假设。当环境存在时，期望所有的相空间都被探索，最终导致稳定。值得注意的例外是无消相干的子空间，它对量子技术有着重要的影响，到目前为止只对具有几个自由度的系统进行了研究。在这里，我们确定了防止量子多体系统达到稳定状态的耗散的简单和一般条件。我们超越了耗散量子态工程的方法，走向了通常与宏观复杂系统相关的可控的长时间非平稳性。这种相干和振荡的演化构成了量子时间晶体的耗散版本。我们讨论了利用光学晶格中的费米子超冷原子来设计这种复杂动力学的可能性。
The assumption that quantum systems relax to a stationary state in the long-time limit underpins statistical physics and much of our intuitive understanding of scientific phenomena. For isolated systems this follows from the eigenstate thermalization hypothesis. When an environment is present the expectation is that all of phase space is explored, eventually leading to stationarity. Notable exceptions are decoherence-free subspaces that have important implications for quantum technologies and have so far only been studied for systems with a few degrees of freedom. Here we identify simple and generic conditions for dissipation to prevent a quantum many-body system from ever reaching a stationary state. We go beyond dissipative quantum state engineering approaches towards controllable long-time non-stationarity typically associated with macroscopic complex systems. This coherent and oscillatory evolution constitutes a dissipative version of a quantum time crystal. We discuss the possibility of engineering such complex dynamics with fermionic ultracold atoms in optical lattices.