Wang Lebin, Lin Wei, Ruan Banxian, Xiang Yuanjiang, Dai Xiaoyu
School of Physics & Electronics, Hunan University, Changsha 410082, People's Republic of China.
J Phys Condens Matter. 2025 Mar 31;37(18). doi: 10.1088/1361-648X/adc35b.
Non-Hermitian systems reveal a wide range of fascinating physical phenomena beyond those found in Hermitian systems, drawing significant interest. Among these phenomena, the non-Hermitian skin effect (NHSE) is particularly notable. This effect enables the bulk states to collapse toward the boundaries and manifest as localized states. In this study, we report an experimental realization of a tunable higher-order NHSE in the Su-Schrieffer-Heeger (SSH) topolectrical circuits. Our experiments were conducted on specially designed one-dimensional and two-dimensional SSH tight-binding circuit networks. Two types of NHSEs with distinct angular localized modes (the diagonal distributed topological-skin mode and the isolated skin-skin angular mode) have been confirmed theoretically and experimentally. By controlling operational amplifiers and other electronic components, we could predict and tunable the skin effect modes in varying dimensions. The tunable NHSEs can be applied to guide waves into target regions, which can offer a number of valuable potential applications.
非厄米系统展现出了一系列超越厄米系统的迷人物理现象，引发了广泛关注。在这些现象中，非厄米趋肤效应（NHSE）尤为显著。这种效应使体态向边界坍缩并表现为局域态。在本研究中，我们报告了在苏-施里弗-黑格（SSH）拓扑电路中实现可调谐高阶NHSE的实验。我们的实验是在专门设计的一维和二维SSH紧束缚电路网络上进行的。理论和实验均证实了两种具有不同角局域模式的NHSE（对角分布拓扑趋肤模式和孤立趋肤-趋肤角模式）。通过控制运算放大器和其他电子元件，我们能够预测并在不同维度上调谐趋肤效应模式。可调谐NHSE可用于将波引导到目标区域，这可提供许多有价值的潜在应用。
