Print Email Facebook Twitter Ballistic supercurrent discretization and micrometer-long Josephson coupling in germanium Title Ballistic supercurrent discretization and micrometer-long Josephson coupling in germanium Author Hendrickx, N.W. (TU Delft QCD/Veldhorst Lab; TU Delft QuTech Advanced Research Centre; Kavli institute of nanoscience Delft) Tagliaferri, M.L.V. (TU Delft QCD/Veldhorst Lab; TU Delft QuTech Advanced Research Centre; Kavli institute of nanoscience Delft) Kouwenhoven, M. (TU Delft QuTech Advanced Research Centre; Kavli institute of nanoscience Delft) Li, R. (TU Delft QCD/Veldhorst Lab; TU Delft QuTech Advanced Research Centre; Kavli institute of nanoscience Delft) Franke, D.P. (TU Delft QCD/Veldhorst Lab; TU Delft QuTech Advanced Research Centre; Kavli institute of nanoscience Delft) Sammak, A. (TU Delft Business Development) Brinkman, A. (University of Twente) Scappucci, G. (TU Delft QCD/Scappucci Lab; TU Delft QuTech Advanced Research Centre; Kavli institute of nanoscience Delft) Veldhorst, M. (TU Delft QCD/Veldhorst Lab; TU Delft QuTech Advanced Research Centre; Kavli institute of nanoscience Delft) Department Business Development Date 2019 Abstract We fabricate Josephson field-effect transistors in germanium quantum wells contacted by superconducting aluminum and demonstrate supercurrents carried by holes that extend over junction lengths of several micrometers. In superconducting quantum point contacts we observe discretization of supercurrent, as well as Fabry-Pérot resonances, demonstrating ballistic transport. The magnetic field dependence of the supercurrent follows a clear Fraunhofer-like pattern, and Shapiro steps appear upon microwave irradiation. Multiple Andreev reflections give rise to conductance enhancement and evidence a transparent interface, confirmed by analyzing the excess current. These demonstrations of ballistic superconducting transport are promising for hybrid quantum technology in germanium. To reference this document use: http://resolver.tudelft.nl/uuid:f2beb59f-6429-45c3-87e5-a5b75344225a DOI https://doi.org/10.1103/PhysRevB.99.075435 ISSN 2469-9950 Source Physical Review B, 99 (7) Part of collection Institutional Repository Document type journal article Rights © 2019 N.W. Hendrickx, M.L.V. Tagliaferri, M. Kouwenhoven, R. Li, D.P. Franke, A. Sammak, A. Brinkman, G. Scappucci, M. Veldhorst Files PDF PhysRevB.99.075435_1_.pdf 896.79 KB Close viewer /islandora/object/uuid:f2beb59f-6429-45c3-87e5-a5b75344225a/datastream/OBJ/view