Implementation of the Su-Schrieffer-Heeger Model in the Self-Assembly Si-In Atomic Chains on the Si(553)-Au Surface.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 38712346.
- Also identified by DOI 10.1021/acsnano.4c00225 and PMC identifier 11112750.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Indium-decorated Si atomic chains on a stepped Si(553)-Au substrate are proposed as an extended Su-Schrieffer-Heeger (SSH) model, revealing topological end states. An appropriate amount of In atoms on the Si(553)-Au surface induce the self-assembly formation of trimer SSH chains, where the chain unit cell comprises one In atom and two Si atoms, confirmed by scanning tunneling microscopy images and density functional calculations. The electronic structure of the system, examined through scanning tunneling spectroscopy, manifests three electron bands within the Si-In chain, accompanied by additional midgap topological states exclusively appearing at the chain's end atoms. To elucidate the emergence of these topological states, a tight-binding model for a finite-length-extended SSH chain is proposed. Analysis of the energy spectra, density of states functions, and eigenfunctions demonstrates the topological nature of these self-assembled atomic chains.