The critical current-field dependence of a Josephson superlattice

The set of coupled nonlinear equations that describes the phase in the Josephson superlattice is presented. Numerical solutions for the simplest of the stacked junction systems, the two-junction system, are investigated in the stationary state for a number of cases of differing critical current densities and junction spacings as a function of parallel applied magnetic field. The results show that the behavior of the system is determined to a great extent by the higher J/sub c/ junction. The numerical solutions are compared with experimental results obtained from SISIS (superconductor-insulator-superconductor-insulator-superconductor) devices (where the superconductor is Nb and the insulator is Al/sub 2/O/sub 3/) and their significance for the Fraunhofer response of high-T/sub c/ bijunction structures is discussed.<
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