Impact of junction length on supercurrent resilience against magnetic field in InSb-Al nanowire Josephson junctions

TL;DR

This study shows that shorter InSb-Al nanowire Josephson junctions can sustain supercurrent under higher magnetic fields, enhancing their potential for topological superconductivity research.

Contribution

It demonstrates that reducing junction length significantly increases the magnetic field resilience of supercurrent in hybrid nanowire Josephson junctions.

Findings

Supercurrent persists up to 1.3 T in 30 nm-long junctions.

Short junctions embedded in loops show interference at 1 T field.

Junction length critically affects supercurrent resilience against magnetic fields.

Abstract

Semiconducting nanowire Josephson junctions represent an attractive platform to investigate the anomalous Josephson effect and detect topological superconductivity by studying Josephson supercurrent. However, an external magnetic field generally suppresses the supercurrent through hybrid nanowire junctions and significantly limits the field range in which the supercurrent phenomena can be studied. In this work, we investigate the impact of the length of InSb-Al nanowire Josephson junctions on the supercurrent resilience against magnetic fields. We find that the critical parallel field of the supercurrent can be considerably enhanced by reducing the junction length. Particularly, in 30 nm-long junctions supercurrent can persist up to 1.3 T parallel field - approaching the critical field of the superconducting film. Furthermore, we embed such short junctions into a superconducting loop and obtain the supercurrent interference at a parallel field of 1 T. Our findings are highly relevant for multiple experiments on hybrid nanowires requiring a magnetic field-resilient supercurrent.