Structural and electronic properties of the quasi-one-dimensional metallic chains of the Au-induced facets on the Si(5 5 12) surface

Abstract

We have investigated the atomic arrangements and electronic properties of the quasi-one-dimensional (Q1D) atomic chains of the Au-induced facets formed on the clean Si(5 5 12)-$2\ifmmode\times\else\texttimes\fi{}1$ surface. The interchain distances of the two well ordered facet structures are estimated to be 30.2 and $22.8\mathrm{\AA{}}.$ By utilizing linearly polarized synchrotron photons, we also determine a complete band diagram of the surface bands and their symmetry characteristics along the two high symmetry azimuths $(\overline{\ensuremath{\Gamma}}\ensuremath{-}\overline{M}$ and $\overline{\ensuremath{\Gamma}}\ensuremath{-}\overline{X})$ of the surface Brillouin zone. The Q1D nature of the Au-induced atomic chains has been well demonstrated by the extremely anisotropic band dispersions of the Au-induced surface bands in addition to the $2\ifmmode\times\else\texttimes\fi{}1$ surface morphology. We find that while the clean reconstructed $\mathrm{Si}(5512)\ensuremath{-}2\ifmmode\times\else\texttimes\fi{}1$ surface is insulating, the Au-induced chains form a highly anisotropic metallic system.