(Quantum Accelerator) Superconducting-FET Microwave Amplifier for Qubit Readout

Superconducting parametric amplifiers are a key enabling technology for fast, high-fidelity readout of superconducting qubit processors. However, they have shortcomings such as limited power handling capacity, and need bulky auxiliary ferrite-based directional components which makes them difficult to integrate with largescale qubit systems. We propose to build amplifiers that meet all the necessary performance metrics for qubit readout while also being directional and thus easy to integrate with quantum processors. Our approach is to exploit superconducting Field Effect-Transistors (SFETs) built with recently developed superconductor semiconductor hybrid heterostructures which we anticipate can achieve the ultra-low-noise performance of superconducting parametric amplifiers in combination with the attractive features of classic semiconductor amplifier designs such as simple DC biasing, large power handling and directionality. Success would make it possible to integrate qubits and readout devices thus bringing us closer to scalable next-generation quantum-computing hardware.