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

TL;DR

This paper demonstrates that a fully coherent disordered 1D insulator can transition to a metallic state due to thermal effects and resonant tunnelling, altering its resistance behavior and showing medium localisation.

Contribution

It reveals a crossover from insulating to metallic behavior in 1D disordered systems under full coherence, driven by thermal smearing and resonant tunnelling effects.

Findings

Resistance dispersion becomes less than unity.

Mean resistance grows polynomially with system size.

System exhibits medium localisation rather than full insulating behavior.

Abstract

It is believed, that a disordered one-dimensional (1D) wire with coherent electronic conduction is an insulator with the mean resistance <\rho> \simeq e^{2L/\xi} and resistance dispersion \Delta_{\rho} \simeq e^{L/\xi}, where L is the wire length and \xi is 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, \Delta_{\rho} is smaller than unity and tends to be L/\xi - independent, while <\rho> grows with L/\xi first nearly linearly and then polynomially, manifesting the so-called medium localisation.