MINIBAND LANDSCAPE OF DISORDERED DIMER SUPERLATTICES

We investigate numerically the universal quantum fluctuations of the r esistance and conductance in disordered dimer semiconductor superlatti ces. These systems exhibit sets of extended states (in spite of being disordered) due to the resonance induced by the dimer structure. We sh ow that the transmission amplitude tau(E) is a function of the energy of injected electrons and that its main characteristic is a ''center'' where tau(E) approximate to 1. This region of energy can be considere d as consisting of weakly localized states proper of mesoscopic system s. On the other hand, the landscape of the allowed energies is a compl ex one, because close to the band edges, where tau(E) much less than 1 , states are strongly localized. We attempt to understand these two re gions by investigating the universal fluctuation properties of the res istance and conductance in both of them. We also hope that this study will contribute to the knowledge about universal fluctuations in mesos copic systems.