Majorana bound states (MBS) are expected to enable topological qubits that encode quantum information with particularly long coherence times. The qubit state is stored non-locally in the fermion parity of multiple pairs of MBS hosted on a semiconducting-superconducting charge island. Interferometric readout of these qubits requires phase-coherent loops that comprise high-mobility InSb nanowires and Al to enable proximity-induced superconductivity in the semiconductor. Here, we introduce a fundamentally new approach for the realization of these hybrid devices based on a novel technique for the selective deposition of the Al thin films. We combine this technique with atomic hydrogen cleaning of the nanowires to remove native oxide prior to the Al deposition. The induced superconductivity in the nanowires is demonstrated via voltage-bias spectroscopy and by probing the critical currents in InSb Josephson junctions. Moreover, Cooper pair tunneling is studied in mesoscopic InSb/Al islands and parity transitions are investigated as a function of the applied magnetic field. Finally, advanced circuits are introduced that allow to study basic elements of the prospective topological qubit.
*European Research Council, Dutch Organization for Scientific Research, and Microsoft Corp. Station Q
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Presenters
Sebastian Heedt
Delft University of Technology
QuTech, Delft University of Technology
Authors
Sebastian Heedt
Delft University of Technology
QuTech, Delft University of Technology
Marina Quintero Perez
Microsoft Station Q at Delft University of Technology
Microsoft Station Q Delft
Station Q, Microsoft Research
Francesco Borsoi
Delft University of Technology
QuTech, Delft University of Technology
Delft University of Technology, QuTech
Alexandra Fursina
Microsoft Station Q at Delft University of Technology
Station Q, Microsoft Research
Nick van Loo
Delft University of Technology
Jie Shen
Delft University of Technology
QuTech and Kavli Institute of Nanoscience, Delft University of Technology
Delft University of Technology, QuTech
Chien-An Wang
Delft University of Technology
Kevin Van Hoogdalem
Microsoft Station Q at Delft University of Technology
Microsoft Station Q Delft
Station Q, Microsoft Research
Badawy Ghada
Eindhoven University of Technology
TU Eindhoven
Sasa Gazibegovic
Applied Physics, Eindhoven University of Technology
Eindhoven University of Technology
Applied Physics, Eindhoven Univ. of Technology
Department of Applied Physics, Eindhoven University of Technology
TU Eindhoven
Eindhoven University of Technology, Department of Applied Physics
Erik P. A. M. Bakkers
Applied Physics, Eindhoven University of Technology
Eindhoven University of Technology
Applied Physics, Eindhoven Univ. of Technology
Department of Applied Physics, Eindhoven University of Technology
TU Eindhoven
Eindhoven University of Technology, Department of Applied Physics
Physics, TU Eindhoven
Leo P Kouwenhoven
Microsoft Station Q at Delft University of Technology
Microsoft Quantum Delft
Qutech, Delft University of Technology
QuTech, Delft University of Technology
Station Q Delft, Microsoft
Microsoft Station Q Delft
Microsoft Station-Q at Delft University of Technology
Microsoft Station Q Delft, Delft University of Technology