Conductance Distribution in Disordered Quantum Wires with a Perfectly Conducting Channel

TL;DR

This paper investigates how a perfectly conducting channel affects conductance distribution in disordered quantum wires, revealing that such channels prevent localization and significantly alter conductance statistics.

Contribution

It demonstrates the stabilization of a perfectly conducting channel in imbalanced quantum wires and analyzes its impact on conductance distribution through numerical simulations.

Findings

Conductance converges to unity in the long-wire limit with a perfectly conducting channel.

The conductance distribution is notably modified by the presence of a perfectly conducting channel.

Absence of Anderson localization due to the stabilized conducting channel.

Abstract

We study the conductance of phase-coherent disordered quantum wires focusing on the case in which the number of conducting channels is imbalanced between two propagating directions. If the number of channels in one direction is by one greater than that in the opposite direction, one perfectly conducting channel without backscattering is stabilized regardless of wire length. Consequently, the dimensionless conductance does not vanish but converges to unity in the long-wire limit, indicating the absence of Anderson localization. To observe the influence of a perfectly conducting channel, we numerically obtain the distribution of conductance in both cases with and without a perfectly conducting channel. We show that the characteristic form of the distribution is notably modified in the presence of a perfectly conducting channel.