Print Email Facebook Twitter Hard superconducting gap in germanium Title Hard superconducting gap in germanium Author Tosato, A. (TU Delft QCD/Scappucci Lab; TU Delft QuTech Advanced Research Centre; Kavli institute of nanoscience Delft) Levajac, V. (TU Delft QRD/Kouwenhoven Lab; TU Delft QuTech Advanced Research Centre; Kavli institute of nanoscience Delft) Wang, J. (TU Delft QRD/Kouwenhoven Lab; TU Delft QuTech Advanced Research Centre; Kavli institute of nanoscience Delft) Boor, Casper J. (Student TU Delft; Kavli institute of nanoscience Delft) Borsoi, F. (TU Delft QCD/Veldhorst Lab; TU Delft QuTech Advanced Research Centre; Kavli institute of nanoscience Delft) Botifoll, Marc (Catalan Institute of Nanoscience and Nanotechnology, Barcelona) Sammak, A. (TU Delft BUS/TNO STAFF) Veldhorst, M. (TU Delft QN/Veldhorst Lab; TU Delft QuTech Advanced Research Centre; Kavli institute of nanoscience Delft) Scappucci, G. (TU Delft QCD/Scappucci Lab; TU Delft QuTech Advanced Research Centre; Kavli institute of nanoscience Delft) Date 2023 Abstract The co-integration of spin, superconducting, and topological systems is emerging as an exciting pathway for scalable and high-fidelity quantum information technology. High-mobility planar germanium is a front-runner semiconductor for building quantum processors with spin-qubits, but progress with hybrid superconductor-semiconductor devices is hindered by the difficulty in obtaining a superconducting hard gap, that is, a gap free of subgap states. Here, we address this challenge by developing a low-disorder, oxide-free interface between high-mobility planar germanium and a germanosilicide parent superconductor. This superconducting contact is formed by the thermally-activated solid phase reaction between a metal, platinum, and the Ge/SiGe semiconductor heterostructure. Electrical characterization reveals near-unity transparency in Josephson junctions and, importantly, a hard induced superconducting gap in quantum point contacts. Furthermore, we demonstrate phase control of a Josephson junction and study transport in a gated two-dimensional superconductor-semiconductor array towards scalable architectures. These results expand the quantum technology toolbox in germanium and provide new avenues for exploring monolithic superconductor-semiconductor quantum circuits towards scalable quantum information processing. To reference this document use: http://resolver.tudelft.nl/uuid:5828ef1f-d61e-4c57-9536-5532664a7106 DOI https://doi.org/10.1038/s43246-023-00351-w ISSN 2662-4443 Source Communications Materials, 4 (1) Part of collection Institutional Repository Document type journal article Rights © 2023 A. Tosato, V. Levajac, J. Wang, Casper J. Boor, F. Borsoi, Marc Botifoll, A. Sammak, M. Veldhorst, G. Scappucci Files PDF s43246_023_00351_w.pdf 2.56 MB Close viewer /islandora/object/uuid:5828ef1f-d61e-4c57-9536-5532664a7106/datastream/OBJ/view