Effect of idle region geometry on the magnetic field curves of Nb/Al-AlOx/Nb Josephson junctions

We have experimentally investigated the effect of the relative position of the junction and the idle region on the magnetic field dependence of the critical current in Nb/Al-AlOx/Nb Josephson window junctions. Two different configurations of the idle part have been used, either symmetric or asymmetric with respect to the junction. Two directions of the external magnetic field have also been considered. The results show that the critical current patterns and the critical magnetic field are strongly affected by the geometry of the system and by the field direction.