Critical current periodicity of Josephson junction interferometers

The critical current through a Josephson junction interferometer has been numerically computed taking into consideration the effect of applied and self-induced magnetic fields on the junctions and in the interference loop. The periodicity of the interference pattern is shown to be less than the flux quantum φ0 = hc/2e. Quantitative results are given illustrating the degree of deviation in periodicity from the flux quantum.