Coherent Charge Transport in Ballistic InSb Nanowire Josephson Junctions

TL;DR

This paper demonstrates phase-coherent, ballistic charge transport in InSb nanowire Josephson junctions, showing gate-tunable supercurrent, multiple Andreev reflections, and Fabry-Pérot interference, advancing topological quantum electronics research.

Contribution

It provides the first clear experimental evidence of ballistic, phase-coherent transport in MBE-grown InSb nanowire Josephson junctions, crucial for topological quantum devices.

Findings

Gate-tunable supercurrent observed

Multiple Andreev reflections detected

Periodic critical current modulations consistent with Fabry-Pérot interference

Abstract

Hybrid InSb nanowire-superconductor devices are promising for investigating Majorana modes and topological quantum computation in solid-state devices. An experimental realisation of ballistic, phase-coherent superconductor-nanowire hybrid devices is a necessary step towards engineering topological superconducting electronics. Here, we report on a low-temperature transport study of Josephson junction devices fabricated from InSb nanowires grown by molecular-beam epitaxy and provide a clear evidence for phase-coherent, ballistic charge transport through the nanowires in the junctions. We demonstrate that our devices show gate-tunable proximity-induced supercurrent and clear signatures of multiple Andreev reflections in the differential conductance, indicating phase-coherent transport within the junctions. We also observe periodic modulations of the critical current that can be associated with the Fabry-P\'{e}rot interference in the nanowires in the ballistic transport regime. Our work shows that the InSb nanowires grown by molecular-beam epitaxy are of excellent material quality and hybrid superconducting devices made from these nanowires are highly desirable for investigation of the novel physics in topological states of matter and for applications in topological quantum electronics.