Table of Contents
ISRN Condensed Matter Physics
Volume 2011, Article ID 724384, 5 pages
Research Article

Equivalent Single-Junction Model of Superconducting Quantum Interference Devices in the Presence of Time-Varying Fields

Department of Physics “E. R. Caianiello,” University of Salerno, 84084 Fisciano (SA), Italy

Received 28 July 2011; Accepted 13 September 2011

Academic Editors: N. Hatakenaka, F. Marsiglio, and T. Schurig

Copyright © 2011 R. De Luca. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


The reduced dynamical model of a two-junction quantum interference device is generalized to the case of time-varying externally applied fluxes with a d. c. component and an oscillating addendum whose frequency is comparable with the inverse of the characteristic time for flux dynamics within the superconducting system. From the resulting effective single-junction model for null inductance of the superconducting loop, it can be seen that the critical current of the device shows a dependence on the frequency and amplitude of the oscillating part of the applied flux. It can therefore be argued that the latter quantities can be considered as control parameters in the voltage versus applied flux curves of superconducting quantum interference devices.