What is the role of topology in the propagation of quantum light in photonic lattices? We address this question by studying the propagation of squeezed states in a topological one-dimensional waveguide array, benchmarking our results with those for a topologically trivial localized state, and studying their robustness against disorder. Specifically, we study photon statistics, one-mode and two-mode squeezing, and entanglement generation when the localized state is excited with squeezed light. These quantum properties inherit the shape of the localized state but, more interestingly, and unlike in the topologically trivial case, we find that propagation of squeezed light in a topologically protected state robustly preserves the phase of the squeezed quadrature as the system evolves. We show how this latter topological advantage can be harnessed for quantum information protocols.

中文翻译：

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一维光子拓扑绝缘体中挤压态的正交保护

拓扑学在量子光在光子晶格中的传播中起什么作用？我们通过研究压缩状态在拓扑一维波导阵列中的传播，将我们的结果与拓扑微不足道的局部状态的结果进行基准测试，并研究它们对无序的鲁棒性来解决这个问题。具体来说，我们研究了光子统计、单模和双模挤压以及当局部状态被挤压光激发时的纠缠生成。这些量子特性继承了局域态的形状，但更有趣的是，与拓扑微不足道的情况不同，我们发现，随着系统的发展，受拓扑保护的状态下压缩光的传播稳健地保留了压缩正交的相位。