Electronic-structure calculations of the Cr/GaAs(001) interface

Abstract

The electronic structure of the Cr/GaAs(001) interfaces, both Cr-Ga and Cr-As, are calculated within the surface Green-function matching formalism. The Hamiltonian used is of the tight-binding type with first- and second-order interactions. A basis of one s and three p atomic orbitals for GaAs and five d orbitals for Cr is employed; the interface parameters are taken as the geometric mean of the constituent material matrix elements. Metallic character and enhancement of the Cr magnetic moment at both interfaces, although lower than that of the Cr(001) surface, is found. The local densities of states present interface-induced effects in the energy range of the Cr d-band width, which are important at the first three layers of the GaAs and at the interface layer of the Cr semi-infinite crystals.