Anderson-Mott transition as a quantum glass problem

Abstract

We combine a recent mapping of the Anderson-Mott metal-insulator transition on a random-field problem with scaling concepts for random-field magnets to argue that disordered electrons near an Anderson-Mott transition show glass-like behavior. We first discuss attempts to interpret experimental results in terms of a conventional scaling picture, and argue that some of the difficulties encountered point towards a glassy nature of the electrons. We then develop a general scaling theory for a quantum glass, and discuss critical properties of both thermodynamic and transport variables in terms of it. Our most important conclusions are that for a correct interpretation of experiments one must distinguish between self-averaging and non-self averaging observables, and that dynamical or temperature scaling is not of power-law type but rather activated, i.e. given by a generalized Vogel-Fulcher law. Recent mutually contradicting experimental results on Si:P are discussed in the light of this, and new experiments are proposed to test the predictions of our quantum glass scaling theory.

25pp, REVTeX, 5 ps figs, final version as published

References in corpus (3)

• Quantum Phase Transitions and Conserved Charges
• A Landau Theory for the Metal-Insulator Transition
• The Anderson-Mott Transition as a Random-Field Problem

Cited by in corpus (11)

• Melting of the Electron Glass
• Anomalous diffusion at the Anderson transitions
• Quantum critical behavior of disordered itinerant ferromagnets
• Theory of many-fermion systems
• Observation of non-gaussian conductance fluctuations at low temperatures in Si:P(B) at the metal-insulator transition
• Long-range order versus random-singlet phases in quantum antiferromagnetic systems with quenched disorder
• Magnetic Correlations in the Two Dimensional Anderson-Hubbard Model
• The metal-insulator transition in Si:X: Anomalous response to a magnetic field
• Quantum critical behavior of itinerant ferromagnets
• A metal-insulator transition as a quantum glass problem
• Anderson-Mott Transition in a Magnetic Field: Corrections to Scaling