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Jellybean quantum dots in silicon for qubit coupling

ORAL

Abstract

The small size and excellent integrability of silicon metal-oxide-semiconductor (SiMOS) quantum dot spin qubits make them an attractive system for mass-manufacturable, scaled-up quantum processors. Furthermore, classical control electronics can be integrated on-chip, in-between the qubits, if an architecture with sparse arrays of qubits is chosen. In such an architecture qubits are either transported across the chip via shuttling, or coupled via mediating quantum systems over short-to-intermediate distances. In this presentation, we will report on the charge and spin characteristics of an elongated quantum dot – a so-called jellybean quantum dot – for the prospects of acting as a qubit-qubit coupler. Charge transport, charge sensing and magneto-spectroscopy measurements are performed on a SiMOS quantum dot device at mK temperature, and compared to Hartree-Fock multielectron simulations. At low electron occupancies where disorder effects and strong electron-electron interaction dominate over the electrostatic confinement potential, the data reveals the formation of three coupled dots, akin to a tunable, artificial molecule. One dot is formed centrally under the gate and two are formed at the edges. At high electron occupancies, these dots merge into one large dot with well-defined spin states, verifying that jellybean dots have the potential to be used as qubit couplers in future quantum computing architectures.

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Publication: Z. Wang, et al., Jellybean quantum dots in silicon for qubit coupling and on-chip quantum chemistry, arXiv:2208.04724 (2022)

Presenters

  • 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.

Authors

  • 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.

  • Zeheng Wang

    University of New South Wales

  • Santiago Serrano

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

  • MengKe Feng

    University of New South Wales, 1) University of New South Wales

  • William Gilbert

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

  • Ross Leon

    Quantum Motion, University of New South Wales

  • 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.

  • Philip Mai

    University of New South Wales

  • Dylan Liang

    University of New South Wales

  • Yue Y Huang

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

  • Yue Su

    University of New South Wales

  • 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

  • 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

  • Christopher Escott

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

  • Andrea Morello

    University of New South Wales

  • Henry Yang

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

  • 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.

  • 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.