INTERFACE ELECTRONIC-STRUCTURE BY THE RENORMALIZATION METHOD - THEORYAND APPLICATION TO SB GAAS/

In this paper we present a highly convergent renormalization scheme fo r the computation of Green's functions of interfaces in the case of ti ght-binding models. It allows the calculation of the Green's function of the whole infinite system, which is built up of a stack of a semi-i nfinite solid of material A, an interface region, and a semi-infinite solid of material B. As a first application we analyse the layer-resol ved interface electronic structure of Sb/GaAs(110) and compare the res ults with calculations for (XML)Sb/GaAs(110), x = 1, 2 and 3. We find several interface states in the fundamental band gap of GaAs(110). The ir energy dispersion and orbital composition are discussed in detail. Furthermore, we find that the interface electronic structure of (3ML)S b/Ga-As(110) still differs significantly from that of the system termi nated by a semi-infinite Sb crystal.