STS Study on the Increase of Surface Resistance in Superconducting RF Resonators Due To Local Magnetic Impurities in the Surface.

ORAL

Abstract

It has been shown previously that there exist local magnetic moments in the surface oxide of materials like Nb, and at the surface of Nb samples capped with a thin layer of Re. These local magnetic moments are apparent in STS studies of these samples as localized YSR states within the superconducting gap. To understand the effect YSR states have on the surface resistance a grid of spectra on a sample's surface can be averaged into one spectrum, and fit using the Kubo-Gurevich proximity model with the phenomenological Dynes Γ parameter to account for conductance within the gap. With a Dynes Γ value for the surface of a sample the contribution to surface resistance due to local magnetic moments can be calculated.

*This work was supported by the U.S. Department of Energy, Office of Science, National Quantum Information Science Research Centers, Superconducting Quantum Materials and Systems Center (SQMS), under Contract No. 89243024CSC000002. Fermilab is operated by Fermi Forward Discovery Group, LLC under Contract No. 89243024CSC000002 with the U.S. Department of Energy, Office of Science, Office of High Energy Physics.

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Presenters

  • Seth J Rice

    • Illinois Institute of Technology

Authors

  • Seth J Rice

    • Illinois Institute of Technology

  • Junki Makita

    • Temple University

  • Ellie Han

    • Temple University

  • Sabrina Garattoni

    • Fermilab
    • Fermi National Accelerator Laboratory (Fermilab)
    • Fermi National Accelerator Laboratory (FNAL)
    • Fermi National Accelerator Laboratory

  • Francesco Crisa

    • Fermi National Accelerator Laboratory
    • Fermi National Accelerator Laboratory (Fermilab)
    • Fermi National Accelerator Laboratory (FNAL)
    • Fermilab

  • Mustafa Bal

    • Fermi National Accelerator Laboratory (Fermilab)

  • Akshay A Murthy

    • Fermi National Accelerator Laboratory (Fermilab)

  • Anna Grassellino

    • Fermi National Accelerator Laboratory (Fermilab)
    • Fermi National Accelerator Laboratory, Batavia, Illinois, 60510, USA

  • Maria Iavarone

    • Temple University

  • John Francis Zasadzinski

    • Illinois Institute of Technology