Simultaneous operation of four singlet-triplet qubits in a two-dimensional array of GaAs quantum dots

ORAL

Abstract

The operation of spin-based quantum processors requires the ability to perform simultaneous and fast measurements in qubit arrays, while overcoming challenges like mitigating crosstalk, tuning in large parameter spaces, and calibrating gate-voltage pulses.
We present the simultaneous coherent manipulation and readout of a two-by-two array of singlet-triplet qubits in GaAs in a geometry where all four qubits can in principle be coupled to a multielectron dot located at the center of the array. Using frequency-multiplexed radio-frequency reflectometry to read out four independent charge sensors, each capacitively coupled to one qubit, we monitor via simultaneous single-shot measurements the fluctuating Overhauser gradients within all four qubits and further induce simultaneous coherent exchange rotations within all qubits. Finally, we demonstrate coherent spin-exchange rotations between one qubit and the multielectron dot, suggesting its use as a coherent coupler that may provide on-demand “any-to-any” qubit-qubit connectivities within the array.

*This work was funded by the Danish Innovation Fund.

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Presenters

  • Federico Fedele

    • Univ of Copenhagen
    • Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark

Authors

  • Federico Fedele

    • Univ of Copenhagen
    • Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark

  • Anasua Chatterjee

    • Univ of Copenhagen
    • Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark

  • Saeed Fallahi

    • Purdue University
    • Purdue Univ

  • Geoffrey C. Gardner

    • Purdue University
    • Purdue Univ
    • Microsoft Quantum at Station Q Purdue, Purdue University
    • Purdue University, Microsoft Station Q, West Lafayette, Indiana 47907, USA
    • Microsoft Quantum at station Q Purdue
    • Microsoft Station Q Purdue, Purdue University
    • Birck Nanotechnology Center and Microsoft Quantum Purdue, Purdue University

  • Michael Manfra

    • Purdue University
    • Purdue Univ
    • Department of Physics and Astronomy and Microsoft Quantum Purdue, Purdue University, West Lafayette, Indiana 47907 USA
    • Department of Physics and Astronomy and Station Q Purdue, Purdue University
    • Niels Bohr Institute, Microsoft Station Q, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
    • Department of Physics and Astronomy, Purdue University
    • Birck Nanotechnology Center and Microsoft Quantum Purdue, Purdue University

  • Ferdinand Kuemmeth

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