Structural models for Si(553)–Au atomic chain reconstruction

Recent photoemission experiments on Si(553)–Au reconstruction show a one-dimensional band with a peculiar 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 et al 2004 Phys. Rev. B 69 125401). Results for the energetics and the band structures are given. Avenues for future investigation are also outlined.