Surface spin induced 1/<i>f</i> flux noise dependent on SQUID geometry (1)
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. Here, we demonstrate the validity of this model by measuring the flux noise amplitudes of about 50 capacitively shunted flux qubits over a wide range of geometric SQUID parameters. Our results show good agreement with the proposed model assuming independent spins, and may therefore serve as a guide on how to improve SQUID designs to minimize 1/f flux noise.
*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. The views and conclusions contained herein are those of the authors and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of the ODNI, IARPA, the DoD, or the U.S. Government.
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Presenters
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Leon Ding
- Massachusetts Institute of Technology MIT
- Research Laboratory of Electronics, Massachusetts Institute of Technology