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

Oral-In-person

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.

–

Presenters

  • Seth Rice

    • Illinois Institute of Technology

Authors

  • Seth Rice

    • Illinois Institute of Technology

  • Junki Makita

    • Temple University

  • Ellie Han

  • Sabrina Garattoni

    • Fermilab

  • Francesco Crisa

  • Mustafa Bal

    • Fermi National Accelerator Laboratory (Fermilab)

  • Akshay Murthy

    • Fermi National Accelerator Laboratory (Fermilab)

  • Anna Grassellino

    • Fermi National Accelerator Laboratory (Fermilab)

  • Maria Iavarone

    • Temple University

  • John Zasadzinski

    • Illinois Institute of Technology