Quantum coherence in ergodic and many-body localized systems
Quantum coherence in ergodic and many-body localized systems
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DOI：
10.1103/physrevb.102.045140
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发表时间：
2020-02
影响因子：
3.7
通讯作者：
S. Dhara;A. Hamma;E. Mucciolo
中科院分区：
文献类型：
--
作者：
S. Dhara;A. Hamma;E. Mucciolo
量子相干性量化了量子态在给定基础上可以具有的叠加量。由于遍历和多体定域系统的本征态结构不同，我们期望它们在给定基上的相干性也不同。在这里，我们数值计算不同的措施，量子相干性的相互作用的无序哈密顿的无序的函数的激发本征态。我们表明，量子相干性可以被用来作为一个序参量来检测研究的遍历多体局域相变。我们还进行量子猝灭研究，以区分热化和本地化阶段的相干性的行为。然后，我们提出了一个协议来计算基于测量的本地化的相干性调查的热和多体本地化的阶段。该协议允许人们以非破坏性的方式通过实验研究量子相关性，而不是需要跟踪子系统的测量，这总是破坏相干性和相关性。
Quantum coherence quantifies the amount of superposition a quantum state can have in a given basis. Since there is a difference in the structure of eigenstates of the ergodic and many-body localized systems, we expect them also to differ in terms of their coherences in a given basis. Here, we numerically calculate different measures of quantum coherence in the excited eigenstates of an interacting disordered Hamiltonian as a function of the disorder. We show that quantum coherence can be used as an order parameter to detect the well-studied ergodic to many-body-localized phase transition. We also perform quantum quench studies to distinguish the behavior of coherence in thermalized and localized phases. We then present a protocol to calculate measurement-based localizable coherence to investigate the thermal and many-body localized phases. The protocol allows one to investigate quantum correlations experimentally in a non-destructive way, in contrast to measures that require tracing out a subsystem, which always destroys coherence and correlation.