Josephson junctions via anodization of epitaxial Al on an InAs heterostructure

We combine electron beam lithography and masked anodization of epitaxial aluminium to define tunnel junctions via selective oxidation, alleviating the need for wet-etch processing or direct deposition dielectric materials. Applying this technique Josephson in proximity induced superconducting Al-InAs heterostructures, we observe multiple Andreev reflections transport experiments, indicative a high quality junction. further compare mobility density Hall-bars defined wet etching anodization. These results may find utility uncovering new fabrication approaches junction-based qubit platforms.