Self-Consistent Theory of Metal Insulator Transitions in Disordered Systems

Self-consistent theory of electron localization in disordered systems is generalized for the case of interacting electrons. We propose and critically compare a number of possible self-consistency schemes which take into account the lowest perturbation theory contributions over the interaction. Depending on self-consistency scheme we can obtain either the continuous metal-insulator transition or that with the minimal metallic conductivity. Within the continuous transition approach we calculate the frequency dependence of generalized diffusion coefficient both for metallic and insulating phases. We also consider interaction renormalization of the single-electron density of states which demonstrates the growth of the effective pseudogap as system goes from metal to insulator.