The electronic structure of Tb silicide nanowires on Si(001)

The electronic structure of Tb silicide nanowires on planar and vicinal Si(001) surfaces was investigated using scanning tunneling spectroscopy, core-level photoemission spectroscopy, and angle-resolved photoemission spectroscopy. The nanowires are metallic and their formation results in a band bending corresponding almost to flatband conditions on n-type substrates. The chemical core-level shifts of the Si-$2p$ spectral components of the nanowires are independent of the substrate offcut indicating the growth of identical nanowire structures. Using vicinal surfaces a single-domain growth of nanowires is possible, enabling the differentiation of the electronic band structure parallel and perpendicular to the nanowires. In this way, five quasi one-dimensional bands crossing or reaching the Fermi level are found. (paper)