Double Au rows on Si(553) surface

TL;DR

This paper proposes a new structural model for the Au-induced Si(553) surface with two gold chains per terrace, matching experimental data and explaining the observed electronic and topographical properties.

Contribution

A novel stable structural model with two gold chains on Si(553) surface that aligns with experimental coverage, electronic band structure, and STM data.

Findings

Model accounts for 0.48 monolayer Au coverage

Band structure matches photoemission data

STM topography agrees with experiments

Abstract

A new structural model of Au induced Si(553) surface is proposed. The model accounts for recently experimentally found value of the Au coverage, i.e. 0.48 monolayer, which suggests formation of two gold chains on each Si(553) terrace. The resulting structural model, like the models of other vicinal Si surfaces, features the honey-comb chain, but there is no buckling at step edge, which is observed on Si(335)-Au and Si(557)-Au surfaces. The present model is more stable than the models with single Au chain only, and agrees very well with existing experimental data. In particular, calculated band structure, featuring two metallic bands coming from hybridization of the gold in both chains with neighboring Si atoms, perfectly matches the photoemission data. Moreover, theoretical scanning tunneling microscopy topography remains in excellent agreement with the experiment.