From inversion to enhancement of the dc Josephson current in S/F-I-F/S tunnel structures -: art. no. 172511

The dependence of the critical current on relative orientation of the F layers magnetization is analyzed within the microscopic theory of the proximity effect for a junction of two proximity S/F bilayers of a massive superconductor (S) / a thin ferromagnet (F) separated by an insulating (I) barrier. We demonstrate that for the S/F-I-F/S contact critical current can reverse its sign (pi -state of the junction) for the parallel orientation of the F layers magnetization. while for antiparallel alignment an enhancement of the critical current takes place.