Hybrid Superconductor-Quantum Point Contact Devices using InSb Nanowires

TL;DR

This paper demonstrates ballistic transport and proximity-induced superconductivity in InSb nanowires with Al contacts, advancing the development of topological superconductors and Majorana bound states.

Contribution

It provides experimental evidence of ballistic transport and Andreev reflection in InSb nanowires directly interfaced with superconducting aluminum.

Findings

Quantized conductance observed at zero magnetic field.

Ballistic transport confirmed in InSb nanowires.

Proximity effect demonstrated via Andreev reflection.

Abstract

Proposals for studying topological superconductivity and Majorana bound states in nanowires proximity coupled to superconductors require that transport in the nanowire is ballistic. Previous work on hybrid nanowire-superconductor systems has shown evidence for Majorana bound states, but these experiments were also marked by disorder, which disrupts ballistic transport. In this letter, we demonstrate ballistic transport in InSb nanowires interfaced directly with superconducting Al by observing quantized conductance at zero-magnetic field. Additionally, we demonstrate that the nanowire is proximity coupled to the superconducting contacts by observing Andreev reflection. These results are important steps for robustly establishing topological superconductivity in InSb nanowires.