Anomalous relocation of topological states

TL;DR

This paper reveals that a non-Hermitian defect in a 1D topological system can anomalously relocate edge states within the lattice, enabling precise control over their position.

Contribution

It introduces a novel mechanism where non-Hermitian defects can manipulate topological states, a phenomenon not previously documented.

Findings

Non-Hermitian defects can remove and relocate topological edge states.

Wave matching conditions explain the anomalous relocation.

Control over topological state position is achievable through defect engineering.

Abstract

I show that a single embedded non-Hermitian defect in a one-dimensional topological system at certain degrees of non-Hermiticity can remove the topological mode from the edge and restore it inside the lattice at the same place where the non-Hermitian defect is placed. I relate this unexpected phenomenon to the wave matching condition and continuity of the wave function at different sites in the lattice. These findings pave the way for controlling the position of topological states at will.