Simulation of the non-Hermitian Kitaev chain by electrical circuits

We investigate the topological properties of the non-Hermitian Kitaev chain by exploiting the versatility of the circuit. We implement non-reciprocal coupling through a negative impedance converter with current inversion (INIC). By conducting impedance measurements between neighboring nodes, we identify both topologically non-trivial and trivial phases within the circuit’s admittance band dispersion under open boundary conditions (OBC). Our analysis of complex admittance spectra reveals differences when comparing circuits with periodic boundary conditions (PBC) to those with OBC. Furthermore, we observe Z₂ skin effects and Majorana zero modes in the topologically non-trivial phases, which are robust against disorders. Notably, the admittance spectra exhibit remarkable sensitivity to the attenuation of the boundary coupling strength. This AC circuit system serves as a promising platform for investigating topological phenomena, opening avenues for the development of functional devices across various application scenarios.