Integration of two-dimensional transition-metal dichalcogenide superconductors into superconducting circuits operated at DC and GHz frequencies*

Two-dimensional (2D) transition-metal dichalcogenide (TMD) superconductors have unique and desirable properties for integration with conventional superconducting circuits, including the ability to form atomically-flat and clean interfaces with stable tunnel barriers, increased kinetic inductance due to the atomically-thin geometry, and resilience to large in-plane magnetic fields. We created 2D-3D Josephson junction contacts with R=0 and critical currents between 0.15uA-128uA. We study the flux response and observe a Fraunhofer pattern with a frequency proportional to a large fraction of the area of the 2D superconductor. This experimental result is confirmed by our numerical modeling, using the Ginzburg-Landau equation to describe screening currents induced in the flake by the magnetic field. We attribute the large effective area and small distortions of the Fraunhofer pattern to the almost uniform penetration of the TMD by the magnetic field and the distribution of screening currents. We have also embedded these 2D-3D contacts in an RF tank circuit (Q>4000) to measure the kinetic inductance. Our work lays the foundation for the analysis of TMD nano-devices in superconducting circuits.