Materials exploration towards high coherence superconducting qubits

ORAL

Abstract

Superconducting quantum circuits are one of the leading platforms for quantum information processing. Tremendous progress has been made in extending the qubit lifetime over the past two decades. It has become clear that further improvement in qubit T1 is possible with reduction/elimination of lossy materials at various surfaces and interfaces by exploration of novel materials and fabrication processes. Our recent work at SQMS Center demonstrated T1 enhancement up to a factor of five in Nb qubits capped with a Ta passivation layer [1]. We attribute this improvement to the replacement of native Nb oxide layer with native Ta oxide, which is thinner and less disordered. We have expanded our work to explore annealing of Ta capped Nb films, substrate preparation, capping layers that do not form an oxide layer such as proximitized Au, and other superconducting base metal layers such as Ta and Re. The results of a systematic study, including the statistics of qubit T1 measurements, will be presented.

This material is based upon work 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 number DE-AC02-07CH11359.

[1] M. Bal et al., arXiv:2304.13257 (2023)

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Publication: M. Bal et al., arXiv:2304.13257 (2023)

Presenters

  • Mustafa Bal

    Fermilab, Fermi National Accelerator Laboratory

Authors

  • Mustafa Bal

    Fermilab, Fermi National Accelerator Laboratory

  • Francesco Crisa

    Fermi National Accelerator Laboratory, Illinois Institute of Technology, Fermilab, Illinois Institute of Technology

  • Akshay A Murthy

    Fermilab, Fermi National Accelerator Laboratory

  • Sabrina Garattoni

    Fermilab, FermiLab, Fermi National Accelerator Laboratory

  • Shaojiang Zhu

    Fermilab, Fermi National Accelerator Laboratory

  • ZuHawn Sung

    Fermilab, Fermi National Accelerator Laboratory

  • Jaeyel Lee

    Fermilab, Fermi National Accelerator Laboratory

  • David v van Zanten

    Fermilab, Fermi National Accelerator Laboratory

  • Ivan Nekrashevich

    Fermi National Accelerator Laboratory

  • Alexander Romanenko

    Fermilab, Fermi National Accelerator Laboratory

  • Peter Hopkins

    National Institute of Standards and Technology, Boulder, National Institute of Standards and Technology Boulder, National Institute of Standards and Technology

  • David Olaya

    University of Colorado, Boulder, CO - National Institute of Standards and Technology, Boulder, National Institute of Standards and Technology, NIST/University of Colorado at Boulder

  • Florent Lecocq

    National Institute of Standards and Technology Boulder, National Institute of Standards and Technology, Boulder, National Institute of Standards and Technology

  • Katarina Cicak

    National Institute of Standards and Technology, Boulder, National Institute of Standards and Technology

  • Michael R Vissers

    National Institute of Standards and Technology

  • Anthony McFadden

    National Institute of Standards and Technology, Boulder, University of California, Santa Barbara, National Institute of Standards and Technology

  • Stephen T Gill

    National Institute of Standards and Technology, Boulder, National Institute of Standards and Technology

  • Corey Rae McRae

    National Institute of Standards and Technology

  • Joel N Ullom

    National Institute of Standards and Technology

  • Anna Grassellino

    Fermilab, Fermi National Accelerator Laboratory