Topolectrical-circuit realization of topological corner modes
Topolectrical-circuit realization of topological corner modes
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DOI：
10.1038/s41567-018-0246-1
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发表时间：
2018-09-01
期刊：
影响因子：
19.6
通讯作者：
Thomale, Ronny
中科院分区：
文献类型：
--
作者：
Imhof, Stefan;Berger, Christian;Thomale, Ronny
量子化电四极绝缘体是近年来提出的一种新的二维量子态。否则，他们可以零维拓扑角落中间间隙状态保护的体光谱间隙，反射对称性和光谱对称性。在这里，我们介绍了一个拓扑电路设计，实现这样的角落模式实验和报告测量中出现的模式作为拓扑边界谐振的角落阻抗分布的电路。而量子化的电子晶体的体四极矩在经典拓扑电路框架中没有直接的模拟，角模继承了量子情况下的相同形式。由于电路的灵活性和可调谐性，它们是详细研究角模反射抗扰特性的理想平台。因此，我们的工作建立了一个实例，其中拓扑电路被用来弥合量子理论建模和拓扑能带结构的实验实现之间的差距。
Quantized electric quadrupole insulators have recently been proposed as novel quantum states of matter in two spatial dimensions. Gapped otherwise, they can feature zero-dimensional topological corner mid-gap states protected by the bulk spectral gap, reflection symmetries and a spectral symmetry. Here we introduce a topolectrical circuit design for realizing such corner modes experimentally and report measurements in which the modes appear as topological boundary resonances in the corner impedance profile of the circuit. Whereas the quantized bulk quadrupole moment of an electronic crystal does not have a direct analogue in the classical topolectrical-circuit framework, the corner modes inherit the identical form from the quantum case. Due to the flexibility and tunability of electrical circuits, they are an ideal platform for studying the reflection symmetry-protected character of corner modes in detail. Our work therefore establishes an instance where topolectrical circuitry is employed to bridge the gap between quantum theoretical modelling and the experimental realization of topological band structures.