# Non-Hermitian anomalous skin effect

## TL;DR

This paper explores the non-Hermitian skin effect in topological insulators, revealing how non-reciprocity influences state localization and enabling control over state transitions.

## Contribution

It demonstrates controllable switching between edge and extended states in a non-Hermitian system with non-reciprocal properties.

## Key findings

- Skin depth decreases with non-reciprocity for bulk states
- Skin depth increases with non-reciprocity for zero energy topological states
- Control over state localization in non-Hermitian topological systems

## Abstract

A non-Hermitian topological insulator is fundamentally different from conventional topological insulators. The non-Hermitian skin effect arises in a nonreciprocal tight binding lattice with open edges. In this case, not only topological states but also bulk states are localized around the edges of the nonreciprocal system. We discuss that controllable switching from topological edge states into topological extended states in a chiral symmetric non-Hermitian system is possible. We show that the skin depth decreases with non-reciprocity for bulk states but increases with it for topological zero energy states.