External magnetic field and self-field effects in stacked long Josephson junctions

We have fabricated and tested samples consisting of two long stacked Josephson junctions with direct access to the intermediate electrode, whose thickness is smaller than London penetration depth lambda(L). The electrodes are patterned so that the junctions can be independently biased in the overlap geometry. We report the behaviour of the critical current of one junction as a function of an applied magnetic field (while the other junction is unbiased) and as a function of the bias current along the McCumber curve in the other junction. We find strong similarity in the two cases and compare the experimental results with numerical simulation.