Flux Qubits Fabricated using a High-Coherence Transmon Fabrication Process

ORAL

Abstract

The coherence of superconducting circuit qubits has dramatically improved since initial implementations, leaping from T1 ~1 ns in early Cooper pair boxes to now attaining ~100 μs in transmons. Much of this improvement has involved careful electromagnetic design paired with fabrication and material research. Our in-house fabrication protocol has been previously optimized for transmons, and we now apply these methods to flux qubits. Numerical simulations were performed to investigate the flux qubit energy spectrum, qubit-resonator coupling, and noise susceptibility to inform design parameters. After optimizing the fabrication process, we present work investigating flux qubits in 3D cavities, in addition to an 8-qubit ring of alternating flux qubits and transmons with nearest neighbor coupling. We perform initial investigations into two-qubit gates between flux qubits and transmons of opposing anharmonicity.

*This work was funded by the Army Research Office. This material is based upon work supported by the National Science Foundation Graduate Research Fellowship Program under Grant No. DGE 1752814. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation.

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Presenters

  • Trevor Chistolini

    • Physics, University of California, Berkeley
    • Univ of California - Berkeley

Authors

  • Trevor Chistolini

    • Physics, University of California, Berkeley
    • Univ of California - Berkeley

  • William Livingston

    • University of California, Berkeley
    • Univ of California – Berkeley
    • Univ of California - Berkeley

  • John Mark Kreikebaum

    • Lawrence Berkeley National Laboratory
    • University of California, Berkeley
    • Univ of California – Berkeley
    • Physics, University of California, Berkeley

  • David Ivan Santiago

    • Lawrence Berkeley National Laboratory
    • University of California, Berkeley
    • Lawrence Berkely National Laboratory
    • Quantum Nanoelectronics Laboratory, Dept. of Physics, University of California, Berkeley

  • Irfan Siddiqi

    • Lawrence Berkeley National Laboratory
    • University of California, Berkeley
    • Univ of California - Berkeley
    • Univ of California – Berkeley
    • Quantum Nanoelectronics Lab, UC Berkeley
    • Physics, University of California, Berkeley
    • Quantum Nanoelectronics Laboratory, Dept. of Physics, University of California, Berkeley