Localization-induced Griffiths phase of disordered Anderson lattices

Abstract

We demonstrate that local density of states fluctuations in disordered Anderson lattice models universally lead to the emergence of non-Fermi liquid (NFL) behavior. The NFL regime appears at moderate disorder (W = W_c) and is characterized by power-law anomalies, e. g. C/T ~ 1/T^{(1-α)}, where the exponent αvaries continuously with disorder, as in other Griffiths phases. This Griffiths phase is not associated with the proximity to any magnetic ordering, but reflects the approach to a disorder-driven metal-insulator transition (MIT). Remarkably, the MIT takes place only at much larger disorder W_{MIT} ~ 12 W_c, resulting in an extraordinarily robust NFL metallic phase.