Josephson junctions with ferromagnetic materials

The current status of the material and interfaces aspects of the problem of SFS Josephson junction fabrication is reviewed and recommendations for selection of ferromagnetic materials are formulated. It is shown that additional pair braking mechanisms at SF interfaces, as well as spin flip and spin orbit scattering in the F films should be taking into account for the data interpretation. The results of theoretical studies of the influence of spin-flip and spin-orbit scattering on the oscillations of critical current with the thickness of the ferromagnetic layers are summarized and discussed. The form of the relation between supercurrent J and order parameters phase difference phi across a junction is analyzed. It is shown that the Josephson current across the structure has the sum of sin phi and sin2 phi components and that two different physical mechanisms are responsible for the sign of sin2 phi.