We carry out a numerical study of the transmittance in a three-dimensional disordered Anderson model and study the weakly localized regime in the vicinity of the mobility edge, by the vector-recursion method of Godin and Haydock. This regime is straddled by stochastic resonant states and characterized by negative magnetoresistance. These stochastic resonances are very different in character to the strong fluctuations in the extended regime which arise due to lead-sample mismatch at the boundary.

• Received 4 March 1994

DOI:https://doi.org/10.1103/PhysRevB.50.4867