Aluminum arsenide cleaved-edge overgrown quantum wires

TL;DR

This paper investigates conductance in aluminum arsenide quantum wires, revealing subband depopulation and conductance reduction due to disorder, with calculations highlighting strain effects on 1D states.

Contribution

It provides the first detailed conductance measurements of aluminum arsenide quantum wires and analyzes the effects of disorder and strain on their 1D electronic properties.

Findings

Observation of conductance steps related to subband depopulation

Substantial reduction in quantum conductance due to disorder

Theoretical demonstration of strain effects on 1D states

Abstract

We report conductance measurements in quantum wires made of aluminum arsenide, a heavy-mass, multi-valley one-dimensional (1D) system. Zero-bias conductance steps are observed as the electron density in the wire is lowered, with additional steps observable upon applying a finite dc bias. We attribute these steps to depopulation of successive 1D subbands. The quantum conductance is substantially reduced with respect to the anticipated value for a spin- and valley-degenerate 1D system. This reduction is consistent with disorder-induced, intra-wire backscattering which suppresses the transmission of 1D modes. Calculations are presented to demonstrate the role of strain in the 1D states of this cleaved-edge structure.