The dominant source of decoherence in frequency tunable superconducting qubits is 1/f flux noise, presumably originating from local magnetic spin impurities located at the surface of their SQUID loops. Here, we measure the flux noise amplitudes of capacitively shunted flux qubits and study their dependence on geometric parameters of their SQUID loops. Our data show good agreement with a previously presented microscopic model for independent spin impurities which has so far eluded experimental verification. We discuss limitations of the proposed model for superconducting films of finite thickness and provide numerical simulations of the current distribution in our SQUIDs, which can refine the considered model. Finally, we apply and confirm our results by observing consistently low flux noise amplitudes in samples with optimized SQUID parameters – small perimeters and large wire widths.
*This research was funded in part by the Office of the Director of National Intelligence (ODNI), Intelligence Advanced Research Projects Activity (IARPA), and the Department of Defense (DoD) via MIT Lincoln Laboratory under Air Force Contract No. FA8721-05-C-0002. Opinions, interpretations, conclusions, and recommendations are those of the authors and are not necessarily endorsed by the US Government.
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Presenters
Jochen Braumueller
Massachusetts Institute of Technology MIT
Research Laboratory of Electronics, Massachusetts Institute of Technology
Massachusetts Institute of Technology
Authors
Jochen Braumueller
Massachusetts Institute of Technology MIT
Research Laboratory of Electronics, Massachusetts Institute of Technology
Massachusetts Institute of Technology
Leon Ding
Massachusetts Institute of Technology MIT
Research Laboratory of Electronics, Massachusetts Institute of Technology
Antti Vepsalainen
Research Laboratory of Electronics, Massachusetts Institute of Technology
Research Laboratory of Electronics, Massachusetts Institute of Technology MIT
Massachusetts Institute of Technology MIT
Youngkyu Sung
Research Laboratory of Electronics, Massachusetts Institute of Technology MIT
Massachusetts Institute of Technology MIT
Research Laboratory of Electronics, Massachusetts Institute of Technology
Massachusetts Institute of Technology
Morten Kjaergaard
Research Laboratory of Electronics, Massachusetts Institute of Technology MIT
Massachusetts Institute of Technology MIT
Research Laboratory of Electronics, Massachusetts Institute of Technology
Massachusetts Institute of Technology
Tim Menke
Harvard Department of Physics, MIT Research Laboratory of Electronics, MIT Department of Physics, Harvard University, Massachusetts Institute of Technology
Massachusetts Institute of Technology MIT
Harvard University; Research Laboratory of Electronics, Massachusetts Institute of Technology
Physics, MIT
Roni Winik
Research Laboratory of Electronics, Massachusetts Institute of Technology
Research Laboratory of Electronics, Massachusetts Institute of Technology MIT
Massachusetts Institute of Technology MIT
Massachusetts Institute of Technology
David K Kim
MIT Lincoln Laboratory
MIT Lincoln Lab
MIT-Lincoln Lab
MIT Lincoln Laboratories
Lincoln Laboratory, Massachusetts Institute of Technology (MIT)
Massachusetts Institute of Technology (MIT) Lincoln Laboratory
Bethany Niedzielski
MIT Lincoln Laboratory
Alexander Melville
MIT Lincoln Laboratory
MIT Lincoln Lab
MIT Lincoln Laboratories
Massachusetts Institute of Technology (MIT) Lincoln Laboratory
Jonilyn Yoder
MIT Lincoln Laboratory
MIT Lincoln Lab
Massachusetts Institute of Technology (MIT) Lincoln Laboratory
Cyrus F. Hirjibehedin
MIT Lincoln Laboratory
University College London, UK
Terry Philip Orlando
Electrical Engineering and Computer Science, Research Laboratory of Electronics, Massachusetts Institute of Technology
Research Laboratory of Electronics, Massachusetts Institute of Technology MIT
Massachusetts Institute of Technology MIT
Electrical Engineering and Computer Science, Massachusetts Institute of Technology
Research Laboratory of Electronics, Massachusetts Institute of Technology
Massachusetts Institute of Technology
MIT Lincoln Laboratory
Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology (MIT)
Simon Gustavsson
Research Laboratory of Electronics, Massachusetts Institute of Technology
Research Laboratory of Electronics, Massachusetts Institute of Technology MIT
Massachusetts Institute of Technology MIT
Massachusetts Institute of Technology
Research Laboratory of Electronics, Massachusetts Institute of Technology (MIT)
William Oliver
Research Laboratory of Electronics, Department of Electrical Engineering and Computer Science, Department of Physics, MIT Lincoln Laboratory, Massachusetts Institute of Techn
MIT Lincoln Lab
MIT Lincoln Laboratory
MIT Lincoln Laboratory, Massachusetts Institute of Technology
Department of Physics, Department of Electrical Engineering and Computer Science, Research Laboratory of Electronics, Lincoln Laboratory, Massachusetts Institute of Technology
Research Laboratory of Electronics, Massachusetts Institute of Technology MIT
Massachusetts Institute of Technology MIT
Department of Electrical Engineering and Computer Science, Department of Physics, Massachusetts Institute of Technology; MIT Lincoln Laboratory
Department of Electrical Engineering and Computer Science, Department of Physics, MIT Lincoln Laboratory, Massachusetts Institute of Technology
Massachusetts Institute of Technology
Research Laboratory of Electronics, Massachusetts Institute of Technology
Research Laboratory of Electronics, Department of Electrical Engineering & Computer Science, Department of Physics, Massachusetts Institute of Technology and MIT Lincoln Labo
Physics, MIT
MIT-Lincoln Lab
MIT Lincoln Laboratories
Research Laboratory of Electronics, Department of Physics, Department of Electrical Engineering and Computer Science, Lincoln Laboratory, Massachusetts Institute of Technolog