Josephson current in ballistic Nb/InAs/Nb highly transmissive junctions
Francesco Giazotto, Kasper Grove-Rasmussen, Rosario Fazio, Fabio Beltram, Edmund H. Linfield, David A. Ritchie
Abstract
Highly transmissive ballistic junctions are demonstrated between Nb and the two-dimensional electron gas formed at an InAs/AlSb heterojunction. A reproducible fabrication protocol is presented yielding high critical supercurrent values. Current-voltage characteristics were measured down to 0.4 K and the observed supercurrent behavior was analyzed within a ballistic model in the clean limit. This investigation allows us to demonstrate an intrinsic interface transmissivity approaching 90%. The reproducibility of the fabrication protocol makes it of interest for the experimental study of InAs-based superconductor-semiconductor hybrid devices.