Observation of a scale-dependent quantum diffusion near the metal-insulator transition

Abstract

Results are presented on the variation of conductivity with temperature in indium oxide samples with various degrees of disorder. For samples with resistivities around the critical value, the conductivity is observed to increase linearly with temperature. It is argued that this behaviour is a manifestation of a scale-dependent quantum diffusion of the quasi-particle. These experimental results have some implications for the inelastic electron-phonon scattering rate in a disordered metal, and these are briefly discussed.