Unveiling new systematics in the self-assembly of atomic chains on Si(111)

TL;DR

This paper investigates the self-assembly mechanisms of atomic chains on Si(111), revealing how different adsorbates and their valence states influence the formation and symmetry of silicon honeycomb chains, a key nanostructure.

Contribution

It uncovers new systematic relationships between adsorbate valence states and the resulting chain symmetries, expanding understanding of surface reconstruction stability.

Findings

Trivalent adsorbates stabilize silicon honeycomb chains.

Silicon honeycomb chains are a universal building block.

Valence state determines accessible chain symmetries.

Abstract

Self-assembled arrays of atomic chains on Si(111) represent a fascinating family of nanostructures with quasi-one-dimensional electronic properties. These surface reconstructions are stabilized by a variety of adsorbates ranging from alkali and alkaline earth metals to noble and rare earth metals. Combining the complementary strength of dynamical low-energy electron diffraction, scanning tunneling microscopy and angle-resolved photoemission spectroscopy, we recently showed that besides monovalent and divalent adsorbates, trivalent adsorbates are also able to stabilize silicon honeycomb chains. Consequently silicon honeycomb chains emerge as a most stable, universal building block shared by many atomic chain structures. We here present the systematics behind the self-assembly mechanism of these chain systems and relate the valence state of the adsorbate to the accessible symmetries of the chains.