Atomic structure, energetics, and dynamics of topological solitons in Indium chains on Si(111) surfaces

TL;DR

This study combines microscopy and theoretical analysis to elucidate the atomic structure, energetics, and dynamics of topological solitons in indium chains on silicon surfaces, revealing their formation energy, mobility constraints, and electric field effects.

Contribution

It provides the first detailed atomic-level characterization and energetic analysis of topological solitons in In chains on Si(111), including their formation energy and dynamic behavior.

Findings

Soliton formation energy is approximately 60 meV.

Solitons exhibit very low mobility despite low activation energy.

Local electric fields can enhance soliton dynamics.

Abstract

Based on scanning tunneling microscopy and first-principles theoretical studies, we characterize the precise atomic structure of a topological soliton in In chains grown on Si(111) surfaces. Variable-temperature measurements of the soliton population allow us to determine the soliton formation energy to be ~60 meV, smaller than one half of the band gap of ~200 meV. Once created, these solitons have very low mobility, even though the activation energy is only about 20 meV; the sluggish nature is attributed to the exceptionally low attempt frequency for soliton migration. We further demonstrate local electric field-enhanced soliton dynamics.