Gate-Defined Josephson Weak-Links in Monolayer WTe2

Adv Mater. 2023 Sep;35(35):e2301683. doi: 10.1002/adma.202301683. Epub 2023 Jul 24.

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 (WTe2 ) 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. Measurements on gate-defined Josephson weak-link devices fabricated using monolayer WTe2 are reported. It is found that consideration of the 2D 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 WTe2 .

Keywords: josephson junctions; quantum spin Hall insulators; superconductivity; topological insulators; tungsten ditelluride; weak-link.