Stirring by Staring: Measurement-Induced Chirality
Stirring by Staring: Measurement-Induced Chirality
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DOI：
10.1103/physrevx.12.031031
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发表时间：
2021-08
影响因子：
12.5
通讯作者：
Matthew Wampler;B. J. J. Khor-B.-J.-J.-Khor-2112667290;G. Refael;I. Klich
中科院分区：
文献类型：
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作者：
Matthew Wampler;B. J. J. Khor-B.-J.-J.-Khor-2112667290;G. Refael;I. Klich
在量子力学中，观察者必然在系统动力学中发挥积极作用，这使得在不干扰系统的情况下探测系统变得困难。在这里，我们利用这种明显的困难作为将最初微不足道的系统驱动到手性阶段的工具。特别是，我们表明，通过利用重复占据测量的模式，我们可以产生在利布晶格上跳跃的费米子的手性边缘传输。该过程在本质上类似于使用周期性驱动来诱导 Floquet 拓扑绝缘体中的手性边缘传输，同时由于量子测量的非统一性质也表现出新颖的现象。我们详细研究了该过程对测量频率的依赖性，表明在芝诺极限下，系统可以通过经典随机动力学来描述，从而产生受保护的传输。随着测量频率的降低，电荷流也会减少，并且在不进行测量时消失。
In quantum mechanics, the observer necessarily plays an active role in the dynamics of the system, making it difficult to probe a system without disturbing it. Here, we leverage this apparent difficulty as a tool for driving an initially trivial system into a chiral phase. In particular, we show that by utilizing a pattern of repeated occupation measurements we can produce chiral edge transport of fermions hopping on a Lieb lattice. The procedure is similar in spirit to the use of periodic driving to induce chiral edge transport in Floquet topological insulators, while also exhibiting novel phenomena due to the non-unitary nature of the quantum measurements. We study in detail the dependence of the procedure on measurement frequency, showing that in the Zeno limit the system can be described by a classical stochastic dynamics, yielding protected transport. As the frequency of measurements is reduced, the charge flow is reduced and vanishes when no measurements are done.