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Characterizing and Optimizing Qubit Coherence based on SQUID Geometry

ORAL

Abstract

Magnetic flux noise is the dominant source of dephasing in tunable superconducting qubits. While the mechanism behind this 1/f flux noise is poorly understood, it has been proposed that it originates from random fluctuations of spin impurities located on the surface of SQUIDs. A previously proposed microscopic model predicts that flux noise increases with the perimeter and decreases with the wire width of the SQUID loop. We discuss a refinement of the previous model for superconducting films of finite thickness which we validate by measuring the flux noise amplitudes of about 50 capacitively shunted flux qubits over a wide range of geometric SQUID parameters. Our results may therefore serve as a guide on how to improve SQUID designs to minimize 1/f flux noise.

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Presenters

  • Leon Ding

    Research Laboratory of Electronics, Massachusetts Institute of Technology, Massachusetts Institute of Technology MIT

Authors

  • Leon Ding

    Research Laboratory of Electronics, Massachusetts Institute of Technology, Massachusetts Institute of Technology MIT

  • Jochen Braumueller

    Massachusetts Institute of Technology MIT, Massachusetts Institute of Technology, Research Laboratory of Electronics, Massachusetts Institute of Technology, MIT

  • Antti Vepsalainen

    Massachusetts Institute of Technology MIT, Research Laboratory of Electronics, Massachusetts Institute of Technology

  • Youngkyu Sung

    Massachusetts Institute of Technology MIT, Massachusetts Institute of Technology, MIT, Research Laboratory of Electronics, Massachusetts Institute of Technology

  • Morten Kjaergaard

    Massachusetts Institute of Technology MIT, Massachusetts Institute of Technology, Research Laboratory of Electronics, Massachusetts Institute of Technology, MIT

  • Tim Menke

    Harvard Department of Physics, MIT Research Laboratory of Electronics, MIT Department of Physics, MIT Research Laboratory of Electronics, MIT Department of Physics, Harvard Department of Physics, Department of Physics, Massachusetts Institute of Technology, Research Laboratory of Electronics, Massachusetts Institute of Technology

  • Roni Winik

    MIT Research Laboratory of Electronics, Massachusetts Institute of Technology MIT, Massachusetts Institute of Technology, Research Laboratory of Electronics, Massachusetts Institute of Technology, MIT

  • David K Kim

    MIT Lincoln Lab, MIT Lincoln Laboratory, Lincoln Laboratory, MIT, MIT - Lincoln Laboratory, Massachusetts Institute of Technology MIT

  • Bethany Niedzielski

    MIT Lincoln Laboratory, MIT Lincoln Lab, Lincoln Laboratory, MIT, MIT - Lincoln Laboratory, Massachusetts Institute of Technology MIT

  • Alexander Melville

    MIT Lincoln Lab, MIT Lincoln Laboratory, Lincoln Laboratory, MIT, MIT - Lincoln Laboratory

  • Jonilyn Yoder

    MIT Lincoln Laboratory, MIT Lincoln Lab, Research Laboratory of Electronics, Massachusetts Institute of Technology, Lincoln Laboratory, MIT, MIT - Lincoln Laboratory, Massachusetts Institute of Technology MIT

  • Cyrus Hirjibehedin

    MIT Lincoln Laboratory, Lincoln Laboratory, MIT, MIT - Lincoln Laboratory

  • Terry Philip Orlando

    Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology MIT, Massachusetts Institute of Technology MIT, Massachusetts Institute of Technology, Research Laboratory of Electronics, Massachusetts Institute of Technology, MIT, Research Laboratory of Electronics and Department of Electrical Engineering & Computer Science, Massachusetts Institute of Technology, Department of Electrical Engineering & Computer Science, Research Laboratory of Electronics, Massachusetts Institute of Technology

  • Simon Gustavsson

    Research Laboratory of Electronics, Massachusetts Institute of Technology, MIT Research Laboratory of Electronics, Massachusetts Institute of Technology MIT, Massachusetts Institute of Technology, MIT

  • William Oliver

    MIT Lincoln Laboratory, Research Laboratory of Electronics, Massachusetts Institute of Technology, Research Laboratory of Electronics, MIT Lincoln Laboratory, Department of Electrical Engineering and Computer Science, MIT Research Laboratory of Electronics, MIT Lincoln Laboratory, MIT Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology MIT, Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Research Laboratory of Electronics, Massachusetts Institute of Technology, MIT Lincoln Laboratory, MIT, MIT, MIT Lincoln Lab, MIT Lincoln Lab, MIT Lincoln Lab, Massachusetts Institute of Technology, Research Laboratory of Electronics, Department of Electrical Engineering and Computer Science, and Department of Physics, Massachusetts Institute of Technology. MIT Lincoln L, Department of Physics, Department of Electrical Engineering & Computer Science, Research Laboratory of Electronics, MIT Lincoln Laboratory, Massachusetts Institute of Technol, Lincoln Laboratory, Research Laboratory of Electronics, and Department of Electrical Engineering & Computer Science, MIT