INTERFACE-INDUCED LOCALIZATION IN ALSB INAS HETEROSTRUCTURES/

The existence of localized states at perfect InSb-like interfaces in A lSb/InAs superlattices is predicted from ab initio pseudopotential cal culations. Localized states are predicted in both the valence and cond uction bands, the former being identifiable with the interface states proposed by Kroemer, Nguyen, and Brar [J. Vac. Sci. Technol. 10, 1769 (1990)]. The existence of these interface localized states is invoked to explain the reported experimental dependence of the band gap upon i nterface types in such superlattices.