Localization in two- and three-dimensional systems away from the band center

Abstract

Extensive numerical results using finite-size-scaling methods for two-dimensional (2D) and three-dimensional (3D) disordered systems are presented for eigenenergies E different from zero. Single-parameter scaling law is satisfied for all of our results in both 2D and 3D systems. In 2D we find only localized states, however, the localization length does not have its maximum at the band center. In 3D, the dependence of the mobility edge on the strength of the diagonal order is obtained. These results are found to be in satisfactory agreement with the predictions of the coherent-potential approximation and the potential-well analogy.