Qdev seminar by Tom Vethaak, Chalmers University of Technology

Silicide-based Josephson field effect transistors for superconducting qubits

Gatemon qubits offer frequency tunability with a static gate voltage instead of a flux line, using superconducting/semiconducting (S/Sm) devices as gate-tuned Josephson junctions. CMOS integration could be achieved with silicon-based Josephson field-Effect Transistors (JoFETs), which ideally have leads with large superconducting gaps that contact a short channel through high-transparency interfaces. I'll present some experimental results on 50nm gate length PtSi transistors, where at negative gate voltages we see evidence of both suppression of the Schottky barrier and an enhanced proximity effect. I'll share my thoughts on how to achieve stronger coupling in such silicon-based JoFETs.