Epitaxial aluminum contacts to InAs nanowires

TL;DR

This paper presents a novel method for creating epitaxial aluminum contacts on InAs nanowires, enabling barrier-free superconducting contacts crucial for quantum device applications.

Contribution

It introduces a lithography-free technique for epitaxial aluminum contacts and demonstrates controllable insertion of high-band gap layers at the interface.

Findings

Barrier-free electrical contact demonstrated

Superconducting properties characterized at low temperature

High-band gap layers controllably inserted at interface

Abstract

We report a method for making epitaxial superconducting contacts to semiconducting nanowires. The temperature and gate characteristics demonstrate barrier-free electrical contact, and the properties in the superconducting state are investigated at low temperature. Half-covering aluminum contacts are realized without the need of lithography and we demonstrate how to controllably insert high-band gap layers in the interface region. These developments are relevant to hybrid superconductor-nanowire devices that support Majorana zero energy states.