Diameter-dependent conductance of InAs nanowires

TL;DR

This study investigates how the electrical conductance of InAs nanowires varies with diameter, revealing a transition from diffusive to surface-influenced transport as the diameter decreases.

Contribution

It provides a detailed analysis of diameter-dependent conductance within individual nanowires, highlighting the role of surface effects and mobility suppression at small diameters.

Findings

Conductivity is diameter-independent above 40 nm.

Resistance increases and mobility drops for diameters below 40 nm.

Evidence suggests a surface accumulation layer influences conductance.

Abstract

Electrical conductance through InAs nanowires is relevant for electronic applications as well as for fundamental quantum experiments. Here we employ nominally undoped, slightly tapered InAs nanowires to study the diameter dependence of their conductance. Contacting multiple sections of each wire, we can study the diameter dependence within individual wires without the need to compare different nanowire batches. At room temperature we find a diameter-independent conductivity for diameters larger than 40 nm, indicative of three-dimensional diffusive transport. For smaller diameters, the resistance increases considerably, in coincidence with a strong suppression of the mobility. From an analysis of the effective charge carrier density, we find indications for a surface accumulation layer.