On the theory of propagation in random systems

✍ Scribed by V.F. Los'

• Publisher: Elsevier Science
• Year: 1991
• Tongue: English
• Weight: 222 KB
• Volume: 175
• Category: Article
• ISSN: 0921-4526
• DOI: 10.1016/0921-4526(91)90686-9

✦ Synopsis

With the help of a projection operator technique a new representation of the Kubo-Greenwood formula for the conductivity in a disordered system, which contains a vertex function in explicit analytical form, is obtained. The summing up of conventional diagrams in the tight-binding approximation gives an expression for the conductivity tensor which describes the Anderson localization of electrons in a strongly disordered alloy. This expression does not coincide with previous results.

In our opinion, a direct theory of conductivity in strongly disordered systems is absent at this moment. There are some ambiguities in papers dealing with electron localization in such systems (see, e.g., refs. [1,2]).

To re-examine this problem we propose a new and direct approach to the investigation of the conductivity of disordered systems based on a projection operator technique. Let us consider noninteracting electrons scattering on a static potential. The conductivity of such a system is given by the Kubo-Greenwood formula