Anisotropic supercurrent suppression and revivals in a graphene-based Josephson junction under in-plane magnetic fields

Abstract

We report on a tunable Josephson junction formed by a bilayer graphene ribbon encapsulated in WSe$_2$ with superconducting niobium contacts. We characterize the junction by measurements of the magnetic field induced interference pattern, and the AC Josephson effect manifested as "Shapiro steps", examining current dependent hysteresis and junction dynamics. The latter can be tuned by temperature, gate voltage, and magnetic field. Finally, we examine the evolution of the supercurrent when subjected to in-plane magnetic fields. Notably, we observe a strong anisotropy in the supercurrent with respect to the orientation of the in-plane magnetic field. When the field is parallel to the current direction, the supercurrent is suppressed, and shows revivals with increasing magnetic field, whereas it remains almost unaffected when the field is oriented in a perpendicular direction. We suggest that this anisotropy is caused by the dependence of supercurrent interference on the junction geometry.