Structural models for the Si(553)-Au atomic chain reconstruction

TL;DR

This study uses first-principles calculations to analyze structural models of the Si(553)-Au surface, aiming to understand the origin of its unique one-dimensional electronic band and facilitate future exploration of spin-charge separation.

Contribution

It introduces detailed first-principles models for the Si(553)-Au surface based on analogies with similar structures, comparing their energetics and band structures.

Findings

Models based on Si(557)-Au analogy are energetically favorable.

The study provides detailed band structure calculations for proposed models.

It identifies key structural features influencing the surface band.

Abstract

Recent photoemission experiments on the Si(553)-Au reconstruction show a one-dimensional band with a peculiar ~1/4 filling. This band could provide an opportunity for observing large spin-charge separation if electron-electron interactions could be increased. To this end, it is necessary to understand in detail the origin of this surface band. A first step is the determination of the structure of the reconstruction. We present here a study of several structural models using first-principles density functional calculations. Our models are based on a plausible analogy with the similar and better known Si(557)-Au surface, and compared against the sole structure proposed to date for the Si(553)-Au system [Crain JN et al., 2004 Phys. Rev. B 69 125401 ]. Results for the energetics and the band structures are given. Lines for the future investigation are also sketched.