High Magnetic Field Stability in a Planar Graphene-NbSe2 SQUID

Thin NbSe2 retains superconductivity at ahigh in-planemagnetic field up to 30 T. In this work we construct a novel atomicallythin, all van der Waals SQUID, in which current flows between NbSe2 contacts through two parallel graphene weak links. The 2Dplanar SQUID remains uniquely stable at high in-plane field, whichenables tracing critical current interference patterns as a functionof the field up to 4.5 T. From these we extract the evolution of thecurrent distribution up to high fields, demonstrating sub-nanometersensitivity to deviation of current flow from a perfect atomic planeand observing a field-driven transition in which supercurrent redistributesto a narrow channel. We further suggest a new application of the asymmetricSQUID geometry to directly probe the current density in the absenceof phase information.

Automated summary

In this work, a novel atomically thin, all van der Waals SQUID is constructed, in which current flows between NbSe2 contacts through parallel graphene weak links. The 2D planar SQUID remains stable at high in-plane fields, enabling the tracing of critical current interference patterns and the observation of a field-driven transition. The asymmetric SQUID geometry is further suggested for directly probing current density in the absence of phase information.