Fidelity assessment and tomography of symmetrically pulsed 2Q gates in MOS quantum dots.

ORAL

Abstract

Qubits based on silicon are one of the most promising pathways to scalable quantum computing. Recently several groups have demonstrated two-qubit primitive gate fidelities above 99% in Si-SiGe and phosphorus donors in silicon using either interleaved randomized benchmarking or Gate Set Tomography (GST) [1-5]. In this work, we study two-qubit gate fidelities in silicon MOS double quantum dot systems using three similar devices. We use three different quantum characterization, verification, and validation (QCVV) methods; interleaved randomized benchmarking, Fast Bayesian Tomography (FBT) [6] and GST. Using tunable exchange and composite pulses we demonstrate controlled phase gate and decoupled controlled phase gate in two of the three devices and show above 99% fidelity as measured by interleaved randomized benchmarking.

[1] Nielsen et al. Quantum 5, 557 (2021).

[2] Madzik et al. Nature 601 (2022),

[3] Xue et al. Nature 601 (2022)

[4] Noiri et al. Nature 601 (2022),

[5] Mills et al. Sci. Adv. 8 (2022),

[6] T.J. Evans, et al. Phys. Rev. Applied, 17:024068, 2022

*We acknowledge support from the Australian Research Council (FL190100167 and CE170100012), the US Army Research Office (W911NF-17-1-0198), and the NSW Node of the Australian National Fabrication Facility.

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Publication: Planned paper, being written at the moment.

Presenters

  • Tuomo I Tanttu

    • 1) University of New South Wales, 2) Diraq Pty. Ltd
    • 1) University of New South Wales 2) Diraq
    • 1) University of New South Wales, 2) Diraq Pty. Ltd.

Authors

  • Tuomo I Tanttu

    • 1) University of New South Wales, 2) Diraq Pty. Ltd
    • 1) University of New South Wales 2) Diraq
    • 1) University of New South Wales, 2) Diraq Pty. Ltd.

  • Wee Han Lim

    • 1) University of New South Wales, 2) Diraq Pty. Ltd
    • 1) University of New South Wales, 2) Diraq Pty. Ltd.
    • University of New South Wales

  • Yue Y Huang

    • UNSW
    • 1) University of New South Wales
    • University of New South Wales

  • Nard Dumoulin Stuyck

    • UNSW
    • 1) University of New South Wales, 2) Diraq Pty. Ltd.

  • William Gilbert

    • 1) University of New South Wales, 2) Diraq Pty. Ltd
    • 1) University of New South Wales, 2) Diraq Pty. Ltd.

  • MengKe Feng

    • University of New South Wales
    • 1) University of New South Wales

  • Jesus D Cifuentes Pardo

    • University of New South Wales
    • 1) University of New South Wales

  • Amanda E Seedhouse

    • University of New South Wales

  • Christopher Escott

    • 1) University of New South Wales, 2) Diraq Pty. Ltd
    • 1) University of New South Wales, 2) Diraq Pty. Ltd.

  • Kohei M Itoh

    • Keio Univ

  • Michael Thewalt

    • Simon Fraser Univ

  • Fay E Hudson

    • 1) University of New South Wales, 2) Diraq Pty. Ltd
    • 1) University of New South Wales, 2) Diraq Pty. Ltd.
    • University of New South Wales

  • Andrea Morello

    • University of New South Wales

  • Arne Laucht

    • 1) University of New South Wales, 2) Diraq Pty. Ltd
    • 1) University of New South Wales, 2) Diraq Pty. Ltd.
    • University of New South Wales
    • University of New South Wales, Diraq Pty. Ltd.

  • Henry Yang

    • 1) University of New South Wales, 2) Diraq Pty. Ltd
    • 1) University of New South Wales, 2) Diraq Pty. Ltd.
    • UNSW Sydney

  • Andre Saraiva

    • 1) University of New South Wales, 2) Diraq Pty. Ltd
    • 1) University of New South Wales, 2) Diraq Pty. Ltd.
    • UNSW Sydney
    • UNSW
    • Diraq
    • University of New South Wales, Diraq Pty. Ltd.

  • Andrew S Dzurak

    • 1) University of New South Wales, 2) Diraq Pty. Ltd
    • 1) University of New South Wales, 2) Diraq Pty. Ltd.
    • University of New South Wales
    • University of New South Wales, Diraq Pty. Ltd.