Extending Er-doped CeO<sub>2</sub> thin films to Si(001) substrates to facilitate scalable nanophotonics fabrication

ORAL

Abstract

Erbium-doped cerium oxide (Er:CeO2) thin films grown via molecular beam epitaxy (MBE)1 have been shown to be a promising platform for the development of quantum memory, with Er3+ optical and spin coherence times in excess of 0.6 μs.2 The next step towards Er:CeO2-based quantum memory is integration into nanophotonic cavities, for enhancement of our telecom-wavelength optical transition. One approach is to leverage evanescent coupling of Er in the oxide film with silicon photonic cavity-waveguide structures, employing silicon-on-insulator (SOI).3 SOI typically features Si(001) as the exposed growth surface, so we study here the impact of CeO2 growth on Si(001) instead of Si(111). Moving our MBE recipe to (001) substrates yields textured CeO2(011) on Si(001), though we also obtain epitaxial CeO2(001) on SrTiO3(001). Optical measurements show 70% broader inhomogeneous linewidths and 20-40% broader spectral diffusion linewidths for Er:CeO2 grown on (001)-oriented substrates compared to that on (111). We discuss routes to improving these properties in CeO2 on Si(001), in order match or surpass those on Si(111).

(1) G. Grant, et al., APL Materials 12, 021121 (2024).

(2) J. Zhang, et al., arXiv preprint arXiv:2309.16785 (2023).

(3) C. Ji, et al., ACS Nano 18.14 (2024): 9929-9941.

*This work is primarily supported by Q-NEXT, a U.S. Department of Energy Office of Science National Quantum Information Science Research Center, with additional support from the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division. This research was supported by an appointment to the Intelligence Community Postdoctoral Research Fellowship Program at the University of Chicago administered by Oak Ridge Institute for Science and Education (ORISE) through an interagency agreement between the U.S. Department of Energy and the Office of the Director of National Intelligence (ODNI).

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Publication: Planning to submit this research to a journal such as JVST A (if no optical improvement is obtained) or APL Materials (if optical improvement is obtained) under a similar title.

Presenters

  • Gregory D Grant

    • University of Chicago
    • University of Chicago / Argonne National Laboratory

Authors

  • Gregory D Grant

    • University of Chicago
    • University of Chicago / Argonne National Laboratory

  • Ignas Masiulionis

    • University of Chicago

  • Jiefei Zhang

    • Argonne National Laboratory

  • F. Joseph Heremans

    • Argonne Nantional Lab
    • Materials Science Division and X-ray Science Division, Argonne National Laboratory
    • Argonne National Laboratory
    • Argonne National Lab
    • University of Chicago

  • David D Awschalom

    • University of Chicago
    • Pritzker School of Molecular Engineering and Department of Physics, University of Chicago, Chicago, IL, USA
    • Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL 60637, USA.
    • Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL 60637, USA
    • Argonne National Laboratory

  • Supratik Guha

    • Argonne National Laboratory