Inductance dependence of noise properties of a high-Tc dc superconducting quantum interference device

Keiji Enpuku, G. Tokita, T. Maruo

Research output: Contribution to journalArticle

17 Citations (Scopus)

Abstract

Properties of white noise of a high-Tc dc superconducting quantum interference device (SQUID) have been studied using numerical simulation. It is shown that thermal noise at T=77 K significantly affects the noise properties of the SQUID. As a result, dependencies of noise properties on inductance become quite different from conventional results at T=4.2 K. In contrast to the case T=4.2 K, the voltage noise of the SQUID at T=77 K depends very weakly on the inductance, while the transfer function degrades rapidly with inductance. Consequently, rapid degradation of flux noise with inductance, as compared with the case T=4.2 K, is caused mainly by that of the transfer function. These simulation results explain reasonably experimental results reported recently. Therefore, it is necessary to improve the transfer function for the improvement of noise properties in the case of large inductances. Numerical simulation shows that a method for improving the transfer function using resistively shunted inductance or three Josephson junctions, which was proposed by the authors, is also useful for improving noise properties in the case of large inductances.

Original languageEnglish
Pages (from-to)8180-8185
Number of pages6
JournalJournal of Applied Physics
Volume76
Issue number12
DOIs
Publication statusPublished - Dec 1 1994

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inductance
interference
transfer functions
simulation
thermal noise
white noise
Josephson junctions
degradation
electric potential

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)

Cite this

Inductance dependence of noise properties of a high-Tc dc superconducting quantum interference device. / Enpuku, Keiji; Tokita, G.; Maruo, T.

In: Journal of Applied Physics, Vol. 76, No. 12, 01.12.1994, p. 8180-8185.

Research output: Contribution to journalArticle

Enpuku, Keiji ; Tokita, G. ; Maruo, T. / Inductance dependence of noise properties of a high-Tc dc superconducting quantum interference device. In: Journal of Applied Physics. 1994 ; Vol. 76, No. 12. pp. 8180-8185.
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