AB-INITIO LMTO CALCULATION OF THE ELECTRONIC-STRUCTURE OF AN ORDERED MONOLAYER OF SB ON A RELAXED GAAS(110) SURFACE

We present electronic surface states as obtained by a comprehensive an d systematic study of a monolayer of Sb on a relaxed GaAs(110) zinc-bl ende surface using the first-principles full-potential self-consistent linear muffin tin orbital (LMTO) method. By considering the well acce pted epitaxial continued layer structure (ECLS) model we investigate t he surface states in the fundamental band gap along high-symmetry dire ctions of the surface Brillouin zone. For the ordered overlayer Sb/GaA s(110), intrinsic surface states appear in the energy gap region which shift towards the bulk valence and the conduction band region when th e relaxations of the surface atoms are considered. A detailed analysis of the surface and resonance states reveals that they are in excellen t agreement with the available experimental data and the existing pseu dopotential calculations.