Embedding the Yang-Lee quantum criticality in open quantum systems
Embedding the Yang-Lee quantum criticality in open quantum systems
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DOI：
10.1103/physrevresearch.4.033250
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发表时间：
2020-12
影响因子：
4.2
通讯作者：
Norifumi Matsumoto;Masaya Nakagawa;Masahito Ueda
中科院分区：
文献类型：
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作者：
Norifumi Matsumoto;Masaya Nakagawa;Masahito Ueda
杨-李边缘奇点是一种典型的非单一临界现象，伴随着反常的尺度定律。然而，这一关键现象中涉及的假想磁场使其物理实现变得困难。通过调用量子经典对应关系将杨-李边缘奇点嵌入具有辅助量子位的量子系统中，我们演示了开放量子系统中非酉量子临界性的物理实现。这里的非单一临界性被认为是由量子测量后选择引起的异常点处的奇点。
The Yang-Lee edge singularity is a quintessential nonunitary critical phenomenon accompanied by anomalous scaling laws. However, an imaginary magnetic field involved in this critical phenomenon makes its physical implementation difficult. By invoking the quantum-classical correspondence to embed the Yang-Lee edge singularity in a quantum system with an ancilla qubit, we demonstrate a physical realization of the nonunitary quantum criticality in an open quantum system. Here the nonunitary criticality is identified with the singularity at an exceptional point caused by postselection of quantum measurement.