Interaction Effects and Transport in the Localized Phase

Abstract

The enhancement of electronic transport in the localized regime by the electron–electron interactions is discussed both in the incoherent channel, leading to transport via inelastic scattering, and in the coherent channel, via delocalization. For the former channel, a new prediction for the temperature dependence of the conductivity in a weak granular insulator is presented. The delocalization by the interactions is considered by treating interblock transport of more than one particle within the scaling theory of localization. Thus, the latter theory can include some of the effects of the interactions. Two-electron delocalization is the first and most straightforward example for that. A simple physical interpretation is given to earlier results of Dorokhov who found from a transfer matrix formulation that a weakly bound pair of particles in a random potential is delocalized with respect to the separate consituents. A very strongly bound pair obviously behaves like a heavier particle and is more strongly localized. Finally, the delocalization of two interacting quasiparticles above the Fermi sea is considered with some recent modifications.