Semiconductor–metal transition in a square quantum wire system

✍ Scribed by A. John Peter; K. Navaneethakrishnan

• Publisher: Elsevier Science
• Year: 2002
• Tongue: English
• Weight: 116 KB
• Volume: 15
• Category: Article
• ISSN: 1386-9477
• DOI: 10.1016/s1386-9477(02)00457-5

✦ Synopsis

Semiconductor-metal transition in a square quantum wire of the GaAs=GaAlAs system is investigated within the e ective mass approximation. Vanishing of the donor ionization energy as a function of well width and donor concentration suggests that no transition is possible below a well width of 7 nm. Critical impurity concentrations at which the transition occurs increase with reduction in well width. The e ects of Anderson localization and correlation in the Hubbard model are included in a simple way. In general, the critical concentration is one order higher in the square quantum wire system when compared to a quantum well case for lower well widths. When well width is increased it reaches the bulk value in both the cases. The critical concentration is enhanced when a random distribution of impurities is considered.