Recent studies have revealed the counterintuitive possibility that increasing disorder can turn a topologically trivial insulator into a nontrivial insulator, called a topological Anderson insulator (TAI). Here, we propose and experimentally demonstrate a photonic TAI in a two-dimensional disordered gyromagnetic photonic crystal in the microwave regime. We directly observe the disorder-induced topological phase transition from a trivial insulator to a TAI with robust chiral edge states. We also demonstrate topological heterostructures that host edge states at interfaces between domains with different disorder parameters.

中文翻译：

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无序光子晶体中的拓扑安德森绝缘子

最近的研究表明，不断增加的无序性可能会将拓扑琐碎的绝缘体转变为非琐碎的绝缘体，称为拓扑安德森绝缘体（TAI），这与直觉相反。在这里，我们提出并实验证明了在微波条件下二维无序回旋磁光子晶体中的光子TAI。我们直接观察到无序诱导的拓扑相变，从琐碎的绝缘体到具有坚固手性边缘态的TAI。我们还演示了拓扑异质结构，这些异质结构在具有不同无序参数的域之间的接口处承载边缘状态。