Skin effect and excitation spectral of interacting non-Hermitian system

TL;DR

This paper investigates the effects of interactions on the spectral properties and skin effect in a non-Hermitian Su-Schrieffer-Heeger model derived from a spin chain, revealing complex spectral and topological phenomena.

Contribution

It introduces an exact diagonalization study of an interacting non-Hermitian model, highlighting how interactions influence spectral functions, degeneracies, and the skin effect.

Findings

Interaction induces anomalous spectral functions.

Skin effect is evidenced by Green's function correlations.

Interactions alter degeneracy and energy band patterns.

Abstract

The non-Hermitian Su-Schrieffer-Heeger spinless Fermion model with interacting terms is studied by exact diagonalization. The model is derived from the spin chain with damping Dzyaloshinskii-Moriya interaction. The presence of the interaction induce anomalous spectral function. The skin effect is exhibited by the non-diagonal terms of the Green's function, i.e. the spatial correlation. The interaction modifies the degeneracy between the ground state and the first excited state of the half filled systems, as well as between the ground state of the half and half plus one filled systems. The energy bands of the higher excited states within the topological regime have complicated pattern, depending on the sign and amplitude of the interaction.