Van der Waals Josephson junction as a gate tunable emitter

This talk will explore the use of van der Waals (vdW) materials as opposed to conventional materials as Josephson junction (JJ) emitters. VdW materials are uniquely apt for superconducting quantum devices due to their single-crystalline, ultra-low defect density, and lack of dangling bonds. Even more intriguingly, the electronic properties of vdW materials, including carrier density and superconducting gap energy, can be tuned by electrostatic gating. JJs made from vdW materials can be homogeneous across large, ~1000 µm2 areas, making them practical as novel sub-THz JJ emitters whose frequency can be tuned with a gate voltage as opposed to changing the bias current. We present numerical calculations of the emitting properties of gate-tunable vdW Josephson junctions and show that they can meet desirable performance criteria, including narrow linewidths < 1MHz and appreciable output power at the microwatt level.