MBE growth of self-assisted InAs nanowires on graphene

TL;DR

This paper reports on the self-assisted growth of InAs nanowires on graphene using molecular beam epitaxy, analyzing their morphology, structure, and electronic transport properties, including Josephson junction behavior.

Contribution

It demonstrates the growth of high-quality InAs nanowires on various graphene substrates and explores their structural and electronic properties for potential device applications.

Findings

Nanowires with ~50 nm diameter and aspect ratio up to 100 were achieved.

InAs nanowires exhibit semi-ballistic transport behavior.

Multiple Andreev Reflections observed in Josephson junctions indicate coherent superconducting transport.

Abstract

Self-assisted growth of InAs nanowires on graphene by molecular beam epitaxy is reported. Nanowires with diameter of ~50 nm and aspect ratio of up to 100 were achieved. The morphological and structural properties of the nanowires were carefully studied by changing the substrate from bilayer graphene through buffer layer to quasi-free-standing monolayer graphene. The positional relation of the InAs NWs with the graphene substrate was determined. A 30{\deg} orientation configuration of some of the InAs NWs is shown to be related to the surface corrugation of the graphene substrate. InAs NW-based devices for transport measurements were fabricated, and the conductance measurements showed a semi-ballistic behavior. In Josephson junction measurements in the non-linear regime, Multiple Andreev Reflections were observed, and an inelastic scattering length of about 900 nm was derived.