Topological and trivial domain wall states in engineered atomic chains

Seung-Gyo Jeong,Tae-Hwan Kim

doi:10.1038/s41535-022-00424-y

Seung-Gyo Jeong, Tae-Hwan Kim

Open Access

https://doi.org/10.1038/s41535-022-00424-y

Copy DOI

Abstract

In a recent article, Huda et al. demonstrated tuneable topological domain wall states in the c(2$\times$2) chlorinated Cu(100). Their system allows to experimentally tune the domain wall states using atom manipulation by the tip of a scanning tunneling microscope (STM). They have realized topological domain wall states of two prototypical 1D models such as trimer and coupled dimer chains. However, they did not distinguish trivial domain wall states from topological ones in their models. As a result, all states of a specific domain wall are not topological but trivial. Here, we show why the specific domain wall states are trivial and how to make them topological. This topological consideration would provide more clear insight on future studies on topological domain wall states in artificial atomic chains.

Highlights

In a recent article[1], Huda et al demonstrated tuneable topological domain wall states in the c(2 × 2) chlorinated Cu(100)[2]
Before discussing the topology of domain walls, we need to introduce an important constraint in the coupled dimer chains as follows
By coupling two SSH chains, we introduce a coupled dimer chain with four ground states where topological chiral domain wall states can emerge when one of two SSH subchains has an interface between topologically distinct Zak phases[5–8]

Summary

Introduction

In a recent article[1], Huda et al demonstrated tuneable topological domain wall states in the c(2 × 2) chlorinated Cu(100)[2]. When we construct any topological domain walls in coupled dimer chains, we keep in mind that they should be able to be undimerized within reasonable atomic displacements.

Results

Conclusion