Observation of bulk-edge correspondence in topological pumping based on a tunable electric circuit
Observation of bulk-edge correspondence in topological pumping based on a tunable electric circuit
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DOI：
10.1038/s42005-022-00957-5
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发表时间：
2022-07
影响因子：
5.5
通讯作者：
Kenichi Yatsugi;Tsuneya Yoshida;T. Mizoguchi;Y. Kuno;Hideo Iizuka;Y. Tadokoro;Y. Hatsugai
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文献类型：
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作者：
Kenichi Yatsugi;Tsuneya Yoshida;T. Mizoguchi;Y. Kuno;Hideo Iizuka;Y. Tadokoro;Y. Hatsugai
在拓扑阶段，出现了受整体拓扑数保护的局域边态。这种现象被称为体-边对应，它已经在包括拓扑泵在内的各种拓扑系统中得到了理论上的建立。已经有一些关于拓扑边态的实验工作。然而，对整体拓扑数的直接观察仍然具有挑战性。在这里，我们实验观察到可调谐电路系统在拓扑相变附近的拓扑边态和体陈氏数。利用可变电容精确地设计了系统的导纳矩阵，实现了量子霍尔相和拓扑跃迁的经典模拟。实验确定了边态的拓扑数，其中边态的位置在拓扑跃迁中发生了翻转。相应的体陈氏数由Středa的阻抗谱公式确定。我们的电路方案是一个很有前途的平台，可以提供对拓扑现象的重要理解，并为功能能量传递机制打开了可能性。
In topological phases, localized edge states protected by the bulk topological number appear. This phenomenon is known as the bulk-edge correspondence, which has been theoretically established in various topological systems including topological pumping. There have been experimental works on topological edge states. However, direct observation of bulk topological numbers remains challenging. Here, we experimentally observe both topological edge states and bulk Chern numbers near the topological phase transition in a tunable electric circuit system. The admittance matrix of the system is accurately engineered by using variable capacitors, leading to the implementation of classical analogue of the quantum Hall phase and the topological transition. The topological numbers of the edge states are determined experimentally, where the locations of the edge states are flipped in the topological transition. The corresponding bulk Chern numbers are determined by the Středa’s formula to the impedance spectrum. Our electric circuit scheme is a promising platform to provide a crucial understanding of topological phenomena, and opens up the possibility toward functional energy transfer mechanisms.