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 lay ers magnetization is analyzed within the microscopic theory of the proximit y effect for a junction of two proximity S/F bilayers of a massive supercon ductor (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 t he critical current takes place.