Performance of Digital SQUID with Sub-Flux Quantum Feedback Resolution Fabricated using 10 kA/cm2 Nb Process

Digital superconducting quantum interference device (SQUID with Single Flux Quantum (SFQ) feedback operates as a Δ-type oversampling A/D converter. Magnetic flux resolution at Nyquist frequency can be improved by taking sub SFQ feedback resolution and large oversampling ratio. Using high critical cu...

Full description

Saved in:
Bibliographic Details
Published inJournal of physics. Conference series Vol. 1590; no. 1
Main Authors Itagaki, Kohki, Oshima, Itta, Hasegawa, Yuichi, Matsunawa, Ryo, Naruse, Masato, Taino, Tohru, Myoren, Hiroaki
Format Journal Article
LanguageEnglish
Published Bristol IOP Publishing 01.07.2020
Subjects
Converters
Critical current density
Feedback
Magnetic flux
Magnetism
Magnetometers
Nyquist frequencies
Oversampling
Physics
Slew rate
Superconducting quantum interference devices
Online AccessGet full text

Cover

More Information
Summary:Digital superconducting quantum interference device (SQUID with Single Flux Quantum (SFQ) feedback operates as a Δ-type oversampling A/D converter. Magnetic flux resolution at Nyquist frequency can be improved by taking sub SFQ feedback resolution and large oversampling ratio. Using high critical current density Nb process for fabricating SFQ circuits, we expected more higher operation speed for the digital SQUID and resulting to higher magnetic flux resolutions. We expected a performance of the digital SQUID magnetometer fabricated using 10 kA/cm2 Nb process based on CAD layout, with an up/down counter using T2FF cells and parallel SFQ feedback. For the clock frequency of 13 GHz and the Nyquist frequency of 1.587 MHz, the magnetic field noise was lower than 1.5fT/Hz and the slew rate was exceeded 500 mT/s.
ISSN:1742-6588
1742-6596
DOI:10.1088/1742-6596/1590/1/012038