The effect of anisotropy on the semiconductor to semimetal transition of type II semiconductor superlattices

Abstract

We have developed a theory of energy band structure for type II (InAs/GaSb) superlattices based on the 8×8 k.p. matrix Hamiltonian (Bodnar model), which includes the effect of electron-hole (light and heavy holes) interactions. In this model, the effect of non-parabolicity and anisotropy is also included. In type II superlattices electrons and holes are located in different materials whereas in type I superlattices such as GaAs/GaAlAs, electrons and holes are located in the same material. We predicted for the first time that the semiconductor-semimetal transition not only depends on the magnetic field and the superlattice periodicity but also depends on the anisotropy of the band structure. A qualitative agreement is obtained between theory and experiment.