Critical behavior of disordered degenerate semiconductors. II. Spectrum and transport properties in mean-field theory

✍ Scribed by Fradkin, Eduardo

• Book ID: 120828938
• Publisher: The American Physical Society
• Year: 1986
• Tongue: English
• Weight: 372 KB
• Volume: 33
• Category: Article
• ISSN: 1098-0121
• DOI: 10.1103/PhysRevB.33.3263

✦ Synopsis

The critical behavior of disordered degenerate semiconductors is studied within a mean-field theory valid when the number of degeneracy points is large. I show that above two dimensions there is a semimetal-metal transition at a critical impurity concentration. The mean free path and the one-particle density of states exhibit scaling behavior with universal exponents. The transition is smeared at nonzero temperature. An equation of state, relating temperature, disorder, and bare con- ductivity, is presented. In two dimensions, the semimetallic phase is unstable. I show that a locali- zation transition follows except in two dimensions where all states are localized. The bare conduc- tivity appears to be a universal number in two dimensions. Applications to zero-gap semiconductors and other systems are discussed.