Minimising spin relaxation in donor atom qubits in silicon

ORAL

Abstract

Donor electron spin qubits hosted within nanoscale devices have demonstrated seconds-long relaxation times [1-4] at magnetic fields suitable for the operation of spin qubits in silicon of B = 1.5 T. The relaxation rates of these qubits have been shown at milliKelvin temperatures to be mediated by spin-orbit coupling with a B5 dependency on magnetic field for B > 3T with a transition to a B3 dependency at magnetic fields below (B ≤ 3T) particularly in multi-donor quantum dot qubits [4]. We identify the relaxation mechanisms that give rise to this saturation at low field and show how, by atomically engineering the device we can minimise this effect extending T1 to ∼200 seconds at B = 1.5 T.

[1] A. Morello et al., Single-shot readout of an electron spin in silicon, Nature 467, 687 (2010).

[2] T. F. Watson et al., High-fidelity rapid initialization and read-out of an electron spin via the single donor D- charge state, Physical Review Letters 115, 166806 (2015).

[3] B. Weber et al., Spin–orbit coupling in silicon for electrons bound to donors, npj Quantum Information 4, 61 (2018).

[4] T. F. Watson et al., Atomically engineered electron spin lifetimes of 30 s in silicon, Science Advances 3, e1602811 (2017).

*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. M.Y.S. acknowledges an Australian Research Council Laureate Fellowship.The research was undertaken with the assistance of resources and services from the National Computational Infrastructure (NCI) under NCMAS 2020 and 2021 allocation, supported by the Australian Government, and of the computational cluster Katana supported by Research Technology Services at UNSW Sydney.

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Publication: Planned paper: Minimising spin relaxation in donor atom qubits in silicon

Presenters

  • Yu-ling Hsueh

    • University of New South Wales

Authors

  • Yu-ling Hsueh

    • University of New South Wales

  • Daniel Keith

    • UNSW
    • University of New South Wales

  • 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

  • Yousun Chung

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

  • Samuel K Gorman

    • 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