Development and defects control in the qubit hosts for quantum information processing

ORAL

Abstract

The energy levels of rare earth ions (REIs) provide an avenue to coherently convert the quantum information between microwave and telecom optical wavelengths. CaWO4 and YVO4 with a tetragonal crystal symmetry are promising host candidates for REIs and to create solid-state quantum systems. However, the charge fluctuation from paramagnetic defects and magnetic fluctuations from the impurities lead to inhomogeneous spectral broadening of REIs affecting the qubit coherence time and efficiency of photon conversion. Both CaWO4 and YVO4 have oxygen-related paramagnetic defects.

We present our results in the development and characterization of these and related host materials. In YVO4, the V4+ ion is adjacent to an O vacancy and the V4+ leads to a yellow color. In CaWO4 the yellow color is due to W5+. To avoid the O-related paramagnetic defects, we employ our state-of-the-art optical floating zone techniques to grow high-purity crystals, and both crystals were grown in high PO2 environments. In YVO4 growth to compensate for the evaporation of V, the crystals were grown from V-rich compositions. O-related defects were further improved by annealing in O2 atmosphere. We also performed a lanthanide-doping in Ca1-xLnxWO4 and we observed the creation of uncompensated charge-related centers, potentially W5+. The quality of crystals was assessed by x-ray diffraction and EPR. If time permits, other W5+ hosts will be discussed.

* This research was supported by the US Department of Energy, Office of Science, National Quantum Information Science Research Centers, Co-design Center for Quantum Advantage (C2QA). A portion of the synthetic work leveraged facilities supported by the National Science Foundation (Platform for the Accelerated Realization, Analysis, and Discovery of Interface Materials (PARADIM)) under Cooperative Agreement No. DMR-2039380.

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Presenters

  • Satya K Kushwaha

    Institute for Quantum Matter, William H. Miller III Department of Physics and Astronomy, Johns Hopkins University, Princeton University

Authors

  • Satya K Kushwaha

    Institute for Quantum Matter, William H. Miller III Department of Physics and Astronomy, Johns Hopkins University, Princeton University

  • Brandon Wilfong

    Institute for Quantum Matter, William H. Miller III Department of Physics and Astronomy, Johns Hopkins University

  • Shannon Bernier

    Institute for Quantum Matter, William H. Miller III Department of Physics and Astronomy, Johns Hopkins University

  • Abby Neill

    Institute for Quantum Matter, William H. Miller III Department of Physics and Astronomy, Johns Hopkins University

  • Mekhola Sinha

    Institute for Quantum Matter, William H. Miller III Department of Physics and Astronomy, Johns Hopkins University

  • Morgan Dierolf

    Institute for Quantum Matter, William H. Miller III Department of Physics and Astronomy, Johns Hopkins University

  • Aviana Judd

    Institute for Quantum Matter, William H. Miller III Department of Physics and Astronomy, Johns Hopkins University

  • Gannon B Murray

    Institute for Quantum Matter, William H. Miller III Department of Physics and Astronomy, Johns Hopkins University

  • Tyrel M McQueen

    Johns Hopkins University, Institute for Quantum Matter, William H. Miller III Department of Physics and Astronomy, Johns Hopkins University