Mean field theory of the Mott-Anderson transition

We present a theory for disordered interacting electrons that can describe both the Mott and Anderson transitions in the respective limits of zero disorder and zero interaction. We use it to investigate the T=0 Mott-Anderson transition at a fixedelectron density, as the disorder strength is increased. Surprisingly, we find two critical values of disorder W-nfl and W-c. For W >W-nfl, the system enters a ''Griffiths'' phase, displaying metallic non-Fermi liquid behavior. At even stronger disorder, W=W-c >W-nfl the system undergoes a metal-insulator transition, characterized by the linear vanishing of both the typical density of states and the typical quasiparticle weight.