Enhancement of proximity-induced superconductivity in a planar Ge hole gas

Hole gases in planar germanium can have high mobilities combination with strong spin-orbit interaction and electrically tunable g-factors, are therefore emerging as a promising platform for creating hybrid superconductor-semiconductor devices. A key challenge towards Ge-based quantum technologies is the design of high-quality interfaces superconducting contacts that robust against magnetic fields. In this work, by combining assets aluminum, which provides good contact to Ge, niobium, has significant gap, we demonstrate highly transparent low-disordered JoFETs relatively large \IcRn \ products capable withstanding We furthermore ability phase-biasing individual JoFETs, opening up an avenue explore topological superconductivity Ge. The persistence reported devices beyond 1.8 Tesla paves way integrating spin qubits proximity-induced on same chip.