Gate-defined Josephson weak-links in monolayer $\mathrm{WTe_2}$

TL;DR

This paper demonstrates gate-defined Josephson weak-links in monolayer WTe2, highlighting their potential for topological quantum devices by exploring superconducting properties and magnetic interference effects.

Contribution

It introduces a fabrication method for Josephson weak-links in monolayer WTe2 and analyzes their magnetic interference, advancing topological superconducting device development.

Findings

Magnetic interference in WTe2 junctions is influenced by 2D superconducting leads.

Fabrication procedures enable reproducible creation of WTe2-based Josephson devices.

First demonstration of gate-defined Josephson weak-links in monolayer WTe2.

Abstract

Systems combining superconductors with topological insulators offer a platform for the study of Majorana bound states and a possible route to realize fault tolerant topological quantum computation. Among the systems being considered in this field, monolayers of tungsten ditelluride ($\mathrm{WTe_2}$) have a rare combination of properties. Notably, it has been demonstrated to be a Quantum Spin Hall Insulator (QSHI) and can easily be gated into a superconducting state. We report measurements on gate-defined Josephson weak-link devices fabricated using monolayer $\mathrm{WTe_2}$. It is found that consideration of the two dimensional superconducting leads are critical in the interpretation of magnetic interference in the resulting junctions. The reported fabrication procedures suggest a facile way to produce further devices from this technically challenging material and the results mark the first step toward realizing versatile all-in-one topological Josephson weak-links using monolayer $\mathrm{WTe_2}$.