A spin-polarised first principles study of short dangling bond wires on Si(001)

TL;DR

This study uses first-principles density functional calculations to analyze the atomic and electronic structures of short dangling bond wires on Si(001), highlighting the importance of spin-polarisation for odd-length wires to match experimental observations.

Contribution

It demonstrates the necessity of spin-polarised calculations for accurately modeling odd-length dangling bond wires on Si(001), improving agreement with experimental STM data.

Findings

Even length wires are well modeled without spin-polarisation.

Odd length wires require spin-polarised calculations for accuracy.

Spin-polarisation yields quantitative agreement with STM observations.

Abstract

Short dangling bond wires (DB wires), fabricated on H-terminated Si(001) surfaces, show patterns of displacement that depend on their length. We have performed density function calculations, with and without spin-polarisation, designed to investigate the atomic and electronic structure of these wires. As expected, we find that even length wires are accurately modelled by non-spin polarised calculations, whilst odd length wires must be modelled using spin-polarised calculations. In particular, the use of spin-polarisation provides quantative agreement with STM observations, rather than the qualitative agreement reported elsewhere.