Measuring Loss Tangents of Substrates for Superconducting Qubits with Part-per-Billion Precision

ORAL

Abstract

We report precision measurements of dielectric loss tangents in substrates for superconducting qubits using an ultra-high quality factor niobium SRF cavity operating at millikelvin temperatures and low electric fields. Multiple substrate types and surface treatments are compared to assess how processing impacts microwave dissipation. The RF results are correlated with materials analysis, including ToF-SIMS and XPS, to identify dominant loss mechanisms. This combined study links microscopic surface chemistry to macroscopic performance and provides a framework for materials-driven improvements in qubit coherence and device design.

*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 managed by FermiForward Discovery Group, LCC, acting under Contract No. 89243024CSC000002

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Presenters

  • Daniel Bafia

    • Fermi National Accelerator Laboratory (Fermilab)

Authors

  • Daniel Bafia

    • Fermi National Accelerator Laboratory (Fermilab)

  • Akshay A Murthy

    • Fermi National Accelerator Laboratory (Fermilab)

  • Mustafa Bal

    • Fermi National Accelerator Laboratory (Fermilab)

  • Francesco Crisa

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

  • Sabrina Garattoni

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

  • Akanksha Mishra

    • Fermi National Accelerator Laboratory
    • Fermi National Accelerator Lab

  • David van Zanten

    • Fermi National Accelerator Laboratory (Fermilab)

  • Roman M Pilipenko

    • Fermi National Accelerator Laboratory

  • Bektur Abdisatarov

    • Fermi National Accelerator Laboratory

  • Alexander Romanenko

    • Fermi National Accelerator Laboratory (Fermilab)

  • Anna Grassellino

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