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[69] Conductivity in Anderson-type models: a comparative study of critical disorder

Abstract

The conductivity in disordered systems is calculated in terms of electron localisation, at dimensionality d=3 and temperature T=0, within tight-binding models with rectangular, Gaussian, Lorentzian and semi-elliptic probability distributions for the site energies. The method is based on a localisation approach in the sense of Vollhardt and Wolfle (1980, 1982) combined with Velicky’s coherent potential approximation framework for the conductivity under the assumption of a semi-elliptic shape for the unperturbed band. Numerical results for DC conductivities, the critical disorder of the metal-insulator transition and mobility edge trajectories are presented with emphasis on the similarities with and differences from earlier work with and without a conductivity pattern. The sensitivity of the critical disorder to the upper momentum cut-off is tested quantitatively.

Publication
Journal of Physics C: Solid State Physics, Volume 21, Number 36
Source Themes
Edeltraud Kolley
Prof. Dr. rer. nat. habil. Edeltraud Kolley