Resistively shunted dc SQUID coupled to an input coil

Keiji Enpuku, K. Yoshida

Research output: Contribution to journalArticle

14 Citations (Scopus)

Abstract

A theoretical study has been made of a resistively shunted dc SQUID coupled to an input coil. The effect of a circulating current is taken into account. An analytical expression for the circulating current is obtained by replacing the nonlinear Josephson current with a linear ac current generator. It is shown that in the conventional SQUID, the circulating current changes considerably the input impedance seen from the input coil, and that the input impedance becomes nonlinear. As a result, previous optimization conditions of amplifiers and magnetometers, which were obtained by neglecting the circulating current, lead to errors amounting to 40%. In the case of a resistively shunted SQUID, where a damping resistance is attached in parallel with an inductance of the SQUID, it is shown that the circulating current can be suppressed significantly with the damping resistance. Therefore, the change of the input impedance caused by the circulating current can be eliminated in this case.

Original languageEnglish
Pages (from-to)1714-1719
Number of pages6
JournalJournal of Applied Physics
Volume59
Issue number5
DOIs
Publication statusPublished - Dec 1 1986

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coils
impedance
damping
inductance
magnetometers
generators
amplifiers
optimization

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)

Cite this

Resistively shunted dc SQUID coupled to an input coil. / Enpuku, Keiji; Yoshida, K.

In: Journal of Applied Physics, Vol. 59, No. 5, 01.12.1986, p. 1714-1719.

Research output: Contribution to journalArticle

Enpuku, Keiji ; Yoshida, K. / Resistively shunted dc SQUID coupled to an input coil. In: Journal of Applied Physics. 1986 ; Vol. 59, No. 5. pp. 1714-1719.
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