Theoretical Study of Alloys and Superlattices with the Renormalization and Recursion Methods.
Abstract
We have performed extensive tight binding calculations of electronic states in HgTe-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 applied a new modified (two- or n-step) Lanczos method to determine real and imaginary parts of all the components of the wave function amplitude, to confirm or further investigate the complete nodal structure. Furthermore, we have used our results to investigate the question of large vs. small valence band offset for this type of interface. On a separate line of research, we have investigated the linear and nonlinear electrical response of composite systems.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 09, 1997
- Accession Number
- ADA328417
Entities
People
- Liang Fu
- Lorenzo Resca
Organizations
- The Catholic University of America