• DocumentCode
    1025401
  • Title

    A novel modulation technique for 1/f noise reduction in dc SQUIDs

  • Author

    Foglietti, V. ; Gallagher, W.J. ; Koch, R.H.

  • Author_Institution
    Istituto di Elettronica dello Stato Solido CNR, Roma, Italy
  • Volume
    23
  • Issue
    2
  • fYear
    1987
  • fDate
    3/1/1987 12:00:00 AM
  • Firstpage
    1150
  • Lastpage
    1153
  • Abstract
    We describe a novel modulation scheme for dc SQUIDs in flux locked loop applications that cancels the effects of Josephson junction critical current fluctuations. The scheme involves switching the SQUID between three states and detecting the output at the second harmonic of the modulation frequency. With this scheme we have achieved a ten fold reduction of the low frequency flux noise spectral density over that obtained with a conventional flux locked loop readout. A dc SQUID with a 20 pH inductance had a resultant noise spectral density of 10-12 \\Phi \\min{0}\\max {2} /Hz at 0.1 Hz, three times lower than the lowest flux noise previously reported for any SQUID system at this frequency.
  • Keywords
    Josephson device noise; Circuit noise; Critical current; Fluctuations; Frequency; Josephson junctions; Low-frequency noise; Noise level; Noise reduction; SQUIDs; Superconducting device noise;
  • fLanguage
    English
  • Journal_Title
    Magnetics, IEEE Transactions on
  • Publisher
    ieee
  • ISSN
    0018-9464
  • Type

    jour

  • DOI
    10.1109/TMAG.1987.1065126
  • Filename
    1065126
    • Link To Document
    https://search.isc.ac/dl/search/defaultta.aspx?DTC=49&DC=1025401