The disordered Fermi-liquid fixed point and its instabilities

The concept of a disordered Fermi-liquid fixed point is introduced and used to understand various properties of disordered metals within a unifying fr amework. Corrections to scaling near this fixed point give what are commonl y called weak-localization effects. Various instabilities of the disordered Fermi-liquid phase are discussed. These include two distinct types of supe rconducting-to-normal-metal quantum phase transitions. First, the quantum p hase transition from a disordered metal to a conventional superconductor in bulk materials is considered. Second, a quantum phase transition in two di mensions from metallic-like behavior to a novel type of disorder induced, s pin-triplet, even-parity, superconductivity is treated. The paper is conclu ded with a discussion of the nature of the ground state of two-dimensional, disordered electron systems.