Novel superconductor-semiconductor low-noise amplifier based on InAs-Al JJFET

Low-noise amplifiers (LNAs) based on traditional III-V semiconductor transistors can achieve many gigahertz of bandwidth and milliwatts of compression power. However, they miss the quantum-limit by an order of magnitude, making them too noisy to directly amplify the signal from superconducting qubit processors. Recently, Josephson Junction Field Effect Transistors (JJFETs) made from InAs-Al superconductor-semiconductor heterostructures have shown promise for building quantum circuits, thanks to their high carrier mobility and the tunability of their supercurrent. Given this new platform which combines the properties of semiconductors and superconductors, we are developing a gate-voltage-tunable quantum-limited parametric amplifier. The gate voltage knob brings widely tunable frequency range and also provides a means to introduce the pump drive for amplification. We will discuss the circuit design, numerical simulation, fabrication, and experimental results for such a parametric amplifier based on InAs-Al JJFETs.