Abstract
The bias current supply to the large-scale single-flux-quantum (SFQ) circuit is not an easy task, because the bias current to drive the SFQ circuit is never small while the SFQ circuit is very sensitive to the magnetic field. We have measured the stray magnetic field on the chip to reveal its effect to the circuit operation. We experimentally confirmed that the stray magnetic field is strongly affected by the return current spreading in the ground plane. Although this spreading current was eliminated by extracting the return current through the ground contact near the bias input, non-negligible magnetic field mainly due to off-chip current was still observed around the bias pad. We found that the inline location of the ground contact for the current path is effective to reduce this magnetic field. We also investigated the effect of the stray magnetic field on the circuit operation. The result revealed that the magnetic field of 10–20μT is critical for the circuit operation, which corresponds to 0.06–0.12Φ0 for the SQUID loop with a typical area of 20μm×0.6μm.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
