Diffusion and logarithmic corrections to the conductivity of a disordered non-interacting 2D electron gas: power law localisation

摘要: Examines the conductivity of two-dimensional weakly disordered systems. It is shown that in a system there divergence as 1/q probability for an electron to diffuse from state K K+q, and this origin logarithmic term. The method enables authors examine nature 'localisation' which occurs. wavefunctions fall off 1/r at zero temperature infinite specimen cannot be normalised. At finite temperatures inelastic collisions give cut-off distance, decreases with increasing T, but overlapping states near Fermi energy are separated by energies small compared kT, so conduction essentially metallic. term depends on normalisation factor.