Anomalous features in Ic(H)-patterns of multifacet Josephson junctions

Multifacet Josephson junctions (MJJs) with alternating 0 and π facets have been intensively investigated within the last years. The experimental dependence of their critical current on applied magnetic field Ic(H) so far notoriously deviated from theoretical prediction. We have realized MJJs using superconductor-insulator-ferromagnet-superconductor heterostructures where 0 and π regions alternate 40 times. Here we show that anomalous features of Ic(H) are caused by a non-uniform flux density parallel to the barrier resulting from screening currents in the electrodes in the presence of a (parasitic) off-plane field component. Further, we demonstrate that there is a specific ''dead angle'', which may be very close to in-plane field orientation. If the field applied by chance at the dead angle or close to it, the average flux density vanishes, resulting in very anomalous Ic(H). This may lead to erroneous conclusions about the sample quality or even the physics investigated. This effect can also be observed in conventional junctions.