Accession Number : ADA328417

Title :   Theoretical Study of Alloys and Superlattices with the Renormalization and Recursion Methods.

Descriptive Note : Final progress rept. 1 Jun 93-31 Mar 97,

Corporate Author : CATHOLIC UNIV OF AMERICA WASHINGTON DC DEPT OF PHYSICS

Personal Author(s) : Fu, Liang ; Resca, Lorenzo

PDF Url : ADA328417

Report Date : 09 JUN 1997

Pagination or Media Count : 10

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.

Descriptors :   *QUANTUM WELLS, *SUPERLATTICES, *ALLOYS, *WAVE FUNCTIONS, MICROSTRUCTURE, COMPUTATIONS, INTERFACES, CRYSTAL LATTICES, HETEROJUNCTIONS, SEMICONDUCTORS, ELECTRICAL PROPERTIES, NODES, NONLINEAR SYSTEMS, SOLUTIONS(GENERAL), VALENCE BANDS, ELECTRONIC STATES, ELECTROMAGNETIC RADIATION, LINEARITY, RECURSIVE FUNCTIONS, CADMIUM TELLURIDES, TELLURIDES, MERCURY COMPOUNDS, GREENS FUNCTIONS, AMPLITUDE.

Subject Categories : Inorganic Chemistry
      Atomic and Molecular Physics and Spectroscopy
      Quantum Theory and Relativity

Distribution Statement : APPROVED FOR PUBLIC RELEASE