Nonlocal Effective Potentials and the Metal-Insulator Transition in Disordered Systems

Abstract

The metal insulator transition of a disordered electron system is analyzed using a new method based on Renormalization Group (R.G.) analysis. It is found that, close to the transition (0°K), at the lowest order in perturbative expansion, the conductivity vanishes on the metallic side as in the non interacting case: σ<(n-nc)µ, with µ=.5 or 1 depending on the absence or presence of time reversal symmetry in the electron system.