Christian Schönenberger I Search for the Fractional Josephson Effect in Topological and Nontopological MaterialsChristian Schönenberger I

Christian Schönenberger, Department of Physics and Swiss Nanoscience Institute, University of Basel, Switzerland

I will report on our search of the AC Josephson effect of superconducting junctions and weak links obtained from various materials in a “low-ohmic” environment allowing for DC bias. The materials are two-dimensional graphene, Al proximitized InAs, the Dirac semimetal cadmium arsenide, the Weyl semimetal tungsten telluride WTe2, the 3D topological insulator HgTe, InAs nanowires and carbon nanotubes, as well as conventional Al-based reference Josephson junctions. We have studied AC Josephson emission, Shapiro steps, current-phase relations and Fraunhofer patterns, the latter to address the current distribution. Until today, we have not found any clear-cut evidence for topology in any of these systems