Analytical approach to calculate the flux dependent current-voltage characteristics of dc superconducting quantum interference devices

摘要

We have studied analytical expressions for the voltage of Josephson junctions in de superconducting quantum interference devices (SQUIDs). Assuming sinusoidal oscillating currents of the junctions for simplicity and easy computation and using a four-terminal network circuit of the SQUID loop, the junction voltage was calculated analytically for zero external flux and half the flux quantum. The current-voltage characteristics obtained at 0 and 77 K for a SQUID consisting of lump elements were in reasonable agreement with those calculated by using a numerical method solving nonlinear differential equations. The analytical method proved helpful for estimating the characteristics of high-T-c SQUIDs, which have distributed impedance due to the interaction between the high-T-c film and dielectric substrate. (C) 1998 American Institute of Physics. S0021-8979(98)07811-6 References: 9