Finite-admittance topological bounded corner states in the kagome topolectrical circuits

Topolectrical circuits are playing increasingly important roles in the discovery and experimentation of topological matter states in condensed matter physics. Here, we discovered finite-admittance topological bounded corner states concentrated next to corners and lined up along the edge in a kagome topolectrical circuit that introduces long-range coupling capacitor interactions. The topological feature is fully characterized by the bulk polarization. In order to detect the finite-admittance topological bounded corner states by measuring the two-point impedance, the additional grounded capacitors are connected to each node, so that the finite-admittance can be moved to zero. As a result, the topological characteristics and robustness of finite admittance topological bounded corner states are well hinted by a strong resonance peak. Our research provides another alternative method for exploring and verifying the finite energy corner state in higher-order topological insulators.