Side-gate modulation of supercurrent in InSb nanoflag-based Josephson junctions

TL;DR

This paper demonstrates how side-gates can effectively control supercurrent and interference patterns in InSb nanoflag-based Josephson junctions, offering a versatile electrical tuning method for quantum device applications.

Contribution

It introduces the use of side-gates for modulating supercurrent and interference in InSb nanoflag Josephson junctions, expanding the control options beyond traditional back-gates.

Findings

Side-gates can modulate supercurrent in both dissipative and dissipation-less regimes.

Side-gates influence the Fraunhofer interference pattern under magnetic fields.

Electrical control via side-gates is comparable to back-gate tuning.

Abstract

InSb nanoflags, due to their intrinsic spin-orbit interactions, are an interesting platform in the study of planar Josephson junctions. Ballistic transport, combined with high transparency of the superconductor/semiconductor interfaces, was reported to lead to interesting phenomena such as the Josephson diode effect. The versatility offered by the planar geometry can be exploited to manipulate both carrier concentration and spin-orbit strength by electrical means. Here we present experimental results on InSb nanoflag-based Josephson junctions fabricated with side-gates placed in close proximity to the junction. We show that side-gates can efficiently modulate the current through the junction, both in the dissipative and in the dissipation-less regimes, similarly to what obtained with a conventional back-gate. Furthermore, the side-gates can be used to influence the Fraunhofer interference pattern induced by the presence of an external out-of-plane magnetic field.