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Low-crosstalk silicon-fabricated optical waveguides for laser delivery to matter qubits

Clayton L. Craft1,*,†, Nicholas J. Barton2,*, Andrew C. Klug3, Kenneth Scalzi3, Ian Wildemann4, Pramod Asagodu4, Joseph D. Broz5, Nikola L. Porto4, Michael Macalik6 et al.

Anthony Rizzo1, Garrett Percevault1, Christopher C. Tison1, A. Matthew Smith1, Michael L. Fanto1, James Schneeloch1, Erin Sheridan1, Dylan Heberle3, Andrew Brownell2, Vijay S.S. Sundaram7, Venkatesh Deenadayalan7, Matthew van Niekerk7, Evan Manfreda-Schulz7, Gregory A. Howland7, Stefan F. Preble7, Daniel Coleman8,9, Gerald Leake8,9, Alin Antohe8,9, Tuan Vo8,9, Nicholas M. Fahrenkopf8,9, Todd H. Stievater10, Kathy-Anne Brickman-Soderberg1, Zachary S. Smith1, and David Hucul1

  • *These authors contributed equally to this work.
  • †Contact author: clayton.craft.1@us.af.mil
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Phys. Rev. Applied 25, 024055 – Published 18 February, 2026

DOI: https://doi.org/10.1103/jgks-dss2

Abstract

Reliable control of quantum information in matter-based qubits requires precisely applied external fields, and unaccounted-for spatial crosstalk of these fields between adjacent qubits leads to loss of fidelity. We report a CMOS foundry-produced microfabricated silicon nitride (Si3N4) optical waveguide for addressing a chain of eight unequally spaced trapped barium ions, with crosstalk compatible with scalable quantum information processing. The crosstalk-mitigation techniques incorporated into the chip design result in a reduction of the measured optical field by at least 50.8(1.3) dB between adjacent waveguide outputs near 650 nm and similar behavior for devices designed for 493 nm and 585 nm. The waveguide outputs near 650 nm, along with a global laser near 493 nm, have been used to laser cool a chain of eight 138Ba+ ions, and a camera has imaged the resulting fluorescence at 493 nm.

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Corrections

12 March, 2026

Correction: An equal contribution footnote was missing at publication and has been added. Values were missing from the third sentence of the abstract and the fifth sentence of the third-to-last paragraph of Sec. III and have been inserted.

Article Text

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Outline

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Phys. Rev. Applied 25, 024055– Published 18 February, 2026
  • Received 6 August 2024
  • Revised 13 September 2025
  • Accepted 29 September 2025
  • Corrected 12 March 2026
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