Theoretical Study of Alloys and Superlattices with the Renormalization andRecursion Methods

摘要

We have performed extensive tight binding calculations of electronic states inHgTe-CdTe heterojunctions, quantum wells and superlattices. The method of solution is based on the Green's function and a powerful renormalization technique, which is particularly suited for the determination of the electronic wavefunctions. That allows a conclusive identification and analysis of the peculiar interface states that occur in these microstructures, and shows the crucial role played by the s-p mixing. In particular, the critical concentration at which the semimetal-semiconductor transition occurs in the simple alloy turns out to be related to a critical concentration occurring in superlattice alloys, at which interfacial states anti-cross, with maximum s-p mixing. We have also