Reentrant behavior and university in the Anderson transition - art. no. 214202

The three-dimensional Anderson model with a rectangular distribution of sit e disorder displays two distinct localization-delocalization transitions, a gainst varying disorder intensity, for a relatively narrow range of Fermi e nergies. Such transitions are studied through the calculation of Localizati on lengths of quasi-one-dimensional systems by transfer-matrix methods, and their analysis by finite-size scaling techniques. For the transition at hi gher disorder we iind the localization-length exponent nu = 1.60(5) and the limiting scaled localization-length amplitude Lambda (0) =0.57(1), strongl y suggesting universality with the transition at the band center, for which currently accepted values are nu =1.57(2) and Lambda (0) =0.576(2). For th e lower (reentrant) transition, we estimate nu = 1.55(15) and Lambda (0) =0 .55(5), still compatible with universality but much less precise, partly ow ing to significant finite-size corrections.