2D-Material-Based Superconducting Quantum Devices

Two-dimensional van der Waals (vdW) materials are promising platforms for superconducting quantum devices due to their single-crystallinity, low defect density, and lack of dangling bonds. Additionally, vdW materials offer a novel knob of gate-tunable electronic properties, including carrier density and superconducting gap energy, and can be readily combined into quantum device heterostructures such as Josephson junctions (JJs). JJs made from vdW materials can boast homogeneity 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 characterize the dc and microwave electronic properties of vdW materials and show they are compatible with high-quality-factor superconducting quantum devices. We also present numerical calculations of the emitting properties of gate-tunable Josephson junctions based on vdW superconductors and semiconductors and show that they can meet desirable performance criteria, including narrow linewidths < 1 MHz and appreciable output power at the microwatt level.