Observation of size-dependent boundary effects in non-Hermitian electric circuits

TL;DR

This paper experimentally demonstrates how boundary conditions and lattice size influence the non-Hermitian skin effect in electric circuits, highlighting size-dependent boundary effects in non-Hermitian systems.

Contribution

It provides the first experimental observation of size-dependent boundary effects on the non-Hermitian skin effect using electric circuits.

Findings

Admittance spectra are highly sensitive to boundary conditions.

Lattice size and boundary terms jointly affect NHSE strength.

Electric circuits serve as effective platforms for studying non-Hermitian boundary effects.

Abstract

The non-Hermitian systems with the non-Hermitian skin effect (NHSE) are very sensitive to the imposed boundary conditions and lattice size, which leads to size-dependent non-Hermitian skin effects. Here, we report the experimental observation of NHSE with different boundary conditions and different lattice size in a unidirectional hopping model based on a circuit platform. The circuit admittance spectra and corresponding eigenstates are very sensitive to the presence of the boundary. Meanwhile, our experimental results show how the lattice size and boundary terms together affect the strength of NHSE. Therefore, our electric circuit provides a good platform to observe size-dependent boundary effects in non-Hermitian systems.