Spin-split Andreev levels in a quantum dot with superconducting leads: microwave spectroscopy

ORAL

Abstract

We use a hybrid superconductor-semiconductor transmon device to perform spectroscopy of a quantum dot Josephson junction tuned to be in a spin-1/2 ground state with an unpaired quasiparticle. Due to spin-orbit coupling, we resolve two flux-sensitive branches in the transmon spectrum, depending on the spin of the quasi-particle. A finite magnetic field shifts the two branches in energy, favoring one spin state and resulting in the anomalous Josephson effect. We demonstrate the excitation of the direct spin-flip transition using all-electrical control. Manipulation and control of the spin-flip transition allow for the implementation of charging energy protected Andreev spin qubits.

*Research supported by funding from the Dutch Research Council (NWO), the allowance for Top consortia for Knowledge and Innovation (TKI's) from the Dutch Ministry of Economic Affairs, the Microsoft Quantum initiative, the Slovenian Research agency (ARRS), the Spanish Ministry of Science and Innovation and the CSIC Research Platform on Quantum Technologies.

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Publication: Spectroscopy of spin-split Andreev levels in a quantum dot with superconducting leads at preprint server arXiv under https://arxiv.org/abs/2208.09314

Presenters

  • Arno Bargerbos

    • Delft University of Technology
    • Qutech, Delft University of Technology

Authors

  • Arno Bargerbos

    • Delft University of Technology
    • Qutech, Delft University of Technology

  • Marta Pita-Vidal

    • TU Delft
    • Delft University of Technology
    • Qutech, Delft University of Technology

  • Rok Zitko

    • Jozef Stefan Institute
    • University of Ljubljana

  • Lukas Johannes Splitthoff

    • Delft University of Technology
    • Qutech, Delft University of Technology
    • QuTech and Kavli Institute of Nanoscience, Delft University of Technology

  • Lukas Grunhaupt

    • Delft University of Technology

  • Jaap J Wesdorp

    • Delft University of Technology
    • Qutech, Delft University of Technology

  • Yu Liu

    • University of Copenhagen
    • Niels Bohr Institute, University of Copenhagen

  • Leo P Kouwenhoven

    • Delft University of Technology
    • Qutech, Delft University of Technology

  • Ramon Aguado

    • CSIC - Madrid

  • Christian K Andersen

    • Delft University of Technology
    • Qutech, Delft University of Technology
    • QuTech and Kavli Institute of Nanoscience, Delft University of Technology

  • Angela Kou

    • University of Illinois at Urbana-Champaign

  • Bernard Van Heck

    • Leiden University