Barrier-Controlled Multi-Qubit Exchange

ORAL

Abstract

Heisenberg exchange coupling between neighboring electron spins in semiconductor quantum dots provides a powerful tool for coherent qubit manipulation in spin-based quantum computing and quantum information processing. Various other phenomena such as many body localization and time crystals in semiconductor quantum dots also require tunable exchange couplings. However, controlling multiple exchange couplings in large quantum dot arrays proves to be challenging, due to non-linear and non-local dependence of the exchange couplings on the confinement gate voltages. In this work we demonstrate simultaneous control of multiple barrier-induced exchange couplings in a four-qubit processor. We model the dependence of the exchange couplings on all barrier gate voltages, which provides a means of precisely and simultaneously controlling multiple exchange couplings. We demonstrate two-, three-, and four-qubit exchange oscillations, and compare the experimental data to the simulated predictions.

*This research was sponsored the Defense Advanced Research Projects Agency under Grant No. D18AC00025; the Army Research Office under Grant Nos. W911NF16-1-0260, and W911NF-19-1-0167.

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Presenters

  • Haifeng Qiao

    • University of Rochester

Authors

  • Haifeng Qiao

    • University of Rochester

  • Yadav Kandel

    • University of Rochester

  • Saeed Fallahi

    • Physics and Astronomy, Purdue University
    • Purdue University
    • Department of Physics and Astronomy, Microsoft Quantum Purdue, Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, USA
    • Physics, Purdue University

  • Geoff C Gardner

    • Purdue University
    • Birck Nanotechnology Center and Microsoft Quantum Purdue, Purdue University
    • Department of Physics and Astronomy and Station Q Purdue, Purdue University
    • Microsoft Quantum Purdue, Purdue University, West Lafayette, Indiana 47907, USA
    • Microsoft Quantum Purdue
    • Department of Physics and Astronomy, Microsoft Quantum Purdue, Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, USA
    • Physics, Purdue University

  • Michael Manfra

    • Physics and Astronomy, Purdue Univ
    • Department of Physics and Astronomy and Station Q Purdue, Birck Nanotechnology Center, School of Materials Engineering, School of Electrical and Computer Engineering, Purdue
    • Purdue Univ
    • Purdue University
    • Microsoft Quantum at Station Q Purdue
    • Department of Physics and Astronomy, Birck Nanotechnology Center, Microsoft Quantum Purdue, School og Materials Engineering & School of Electrical and Computer Engineering, P
    • Physics and Astronomy, Purdue University
    • Department of Physics and Astronomy and Station Q Purdue, Purdue University
    • Department of Physics and Astronomy and Microsoft Quantum Purdue, Purdue University, West Lafayette, Indiana 47907 USA
    • Department of Physics and Astronomy, PURDUE UNIVERSITY
    • Department of Physics and Astronomy, Microsoft Quantum Purdue, Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, USA
    • Physics, Purdue University

  • John Nichol

    • University of Rochester