Fig. 1
From: A ballistic graphene superconducting microwave circuit
A gate tunable microwave cavity based on an encapsulated graphene Josephson junction. a Optical micrograph of the microwave cavity before placing the BN/G/BN stack. Bright areas are MoRe, dark areas are sapphire substrate. Grey area around the parallel plate capacitors is the Si3N4 shunt dielectric. Scale bar 200 μm. b Optical micrograph of the gJJ. The cavity center line and the ground plane are connected through the gJJ and NbTiN leads. The gate line (right) extends over the entire junction. Scale bar 40 μm. c Close-up of b with the graphene channel indicated. Dark areas are HSQ for gate insulation. Scale bar 5 μm. d Sketch of the device circuit. The input signals are filtered and merged using a bias tee before being fed on to the feedline (see Methods section and Supplementary Fig. 1). e Schematic cross-section of the gJJ with top-gate, not to scale
