Coherent "metallic" resistance and medium localisation in a disordered 1D insulator

Abstract

It is believed, that a disordered one-dimensional (1D) wire with coherent electronic conduction is an insulator with the mean resistance <ρ> \simeq e^{2L/ξ} and resistance dispersion Δ_ρ \simeq e^{L/ξ}, where L is the wire length and ξis the electron localisation length. Here we show that this 1D insulator undergoes at full coherence the crossover to a 1D "metal", caused by thermal smearing and resonant tunnelling. As a result, Δ_ρ is smaller than unity and tends to be L/ξ- independent, while <ρ> grows with L/ξfirst nearly linearly and then polynomially, manifesting the so-called medium localisation.

4 pages, 4 figures, RevTeX4