Readout of singlet-triplet spin qubit in donor-based devices in silicon

ORAL

Abstract

Singlet-triplet qubits have been investigated in gate-defined quantum dot systems where micromagnets are used to generate large magnetic field gradients for high-fidelity electrically-controlled qubit operations. However, the large magnetic field gradients increase the triplet relaxation making readout difficult. Here, we theoretically examine shelving and latching singlet-triplet readout techniques for donor-based devices in silicon where the large phosphorus hyperfine interaction leads to large effective magnetic field gradients. Using numerical simulations, we analyse how devices can be engineered for maximum readout visibility and show that singlet-triplet qubits based on phosphorus donors are a promising route for future electrically controlled qubits in silicon without the need of micromagnet.

*This research was conducted by the Australian Research Council Centre of Excellence for Quantum Computation and Communication Technology (CE170100012), the US Army Research Office under contract number W911NF-17-1-0202 and Silicon Quantum Computing Pty Ltd.

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Presenters

  • Edyta N Osika

    • University of New South Wales

Authors

  • Edyta N Osika

    • University of New South Wales

  • Samuel K Gorman

    • University of New South Wales
    • Silicon Quantum Computing Pty Ltd., Level 2, Newton Building, UNSW Sydney, Kensington, NSW 2052, Australia

  • Serjaum S Monir

    • University of New South Wales
    • UNSW Sydney
    • Centre of Excellence for Quantum Computation and Communication Technology, School of Physics, University of New South Wales, Sydney, New South Wales 2052, Australia

  • Yu-ling Hsueh

    • University of New South Wales

  • Marcus Borscz

    • University of New South Wales

  • Helen Geng

    • University of New South Wales

  • Brandur Thorgrimsson

    • University of New South Wales
    • Silicon Quantum Computing Pty Ltd., Level 2, Newton Building, UNSW Sydney, Kensington, NSW 2052, Australia

  • Michelle Y Simmons

    • University of New South Wales
    • Silicon Quantum Computing Pty Ltd., Level 2, Newton Building, UNSW Sydney, Kensington, NSW 2052, Australia; Centre of Excellence for Quantum Computation and Communication Tec

  • Rajib Rahman

    • University of New South Wales
    • Silicon Quantum Computing Pty Ltd., Level 2, Newton Building, UNSW Sydney, Kensington, NSW 2052, Australia