Hydrogen as a Source of Flux Noise in SQUIDs

POSTER

Abstract


Superconducting qubits are hampered by flux noise produced by fluctuating surface spins from a variety of microscopic sources. Recent experiments indicated that hydrogen (H) atoms may be one of those sources. Using density functional theory calculations, we found sizeable magnetic moments arising from H atoms either embedded in, or adsorbed on, an α-Al2O3(0001) surface. We also find that H adatoms on the surface attract gas molecules such as O2, producing new spin sources. We propose to use a coating layer (e.g., graphene) to eliminate the H-induced magnetization.

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Work was supported in part by DOE-BES Grant No. DE-FG02-05ER46237), National Science Foundation of China under Grant No. 11474056, National Basic Research Program of China grant number 2015CB921400, Google Gift No. 2502, and a grant from the UC Office of the President Multi-campus Research Programs

Presenters

  • Ruqian Wu

    • Univ of California - Irvine
    • Department of Physics and Astronomy, Univ of California - Irvine
    • University of California, Irvine
    • Department of Physics and Astronomy, University of California, Irvine
    • Physics, Univ of California - Irvine

Authors

  • Ruqian Wu

    • Univ of California - Irvine
    • Department of Physics and Astronomy, Univ of California - Irvine
    • University of California, Irvine
    • Department of Physics and Astronomy, University of California, Irvine
    • Physics, Univ of California - Irvine

  • Zhe Wang

    • Department of Physics , Fudan University

  • Hui Wang

    • Univ of California - Irvine
    • Department of Physics and Astronomy, Univ of California - Irvine
    • Physics, Univ of California - Irvine

  • Clare Yu

    • Physics and Astronomy, Univ of California - Irvine
    • Department of Physics and Astronomy, Univ of California - Irvine