A qubit-based oscilloscope for characterizing the distortion of flux pulses for two-qubit gates in circuit QED

ORAL

Abstract

In circuit QED, conditional-phase gates between flux-tunable Transmon qubits can be performed in 40 ns by pulsing fast adiabatically in and out of an avoided crossing in the two-excitation manifold. However, the flux pulses required are subject to distortions due to electrical components both at room temperature and inside the fridge. The room-temperature distortions can be characterized using a conventional oscilloscope and corrected using linear filtering. Correcting the cryogenic distortions is more challenging. We demonstrate a novel protocol that uses the pulsed qubit to directly measure the flux distortions on-chip, creating a cryogenic oscilloscope. We use the cryo-scope and numerical optimization to tune conditional-phase gates to the limit set by decoherence.

*This research is funded by U.S. Army Research Office Grant W911NF-16-1-0071.

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Presenters

  • Michiel Adriaan Rol

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

Authors

  • Michiel Adriaan Rol

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

  • Livio Ciorciaro

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

  • Brian Tarasinski

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

  • Ramiro Sagastizabal

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

  • Cornelis Christiaan Bultink

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

  • Malay Singh

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

  • Leonardo DiCarlo

    • QuTech and Kavli Institute of Nanoscience, Delft University of Technology
    • TUD Faculty of Sciences, QuTech
    • Kavli Institute of Nanoscience Delft, Delft University of Technology