Critical current in S-FNF-S Josephson structures with the noncollinear magnetization vectors of ferromagnetic films

The critical current IC of S-FNF-S Josephson junctions, which are ferromagnet (F)-normal metal (N)-ferromagnet multilayer structures whose ends are in contact with the superconducting (S) electrodes, has been calculated. It has been shown that both the magnitude and sign of IC depends significantly on the misorientation angle α of the magnetization vectors M1, 2 of the ferromagnetic films and the distance L between the superconducting electrodes. The effect of the triplet superconducting component ∼〈ψ↑ψ↑〉 ∼〈ψ↓ψ↓〉 appearing in the structure on IC(α) has been analyzed. It has been proven that a new type of the π junction exists, appearing due to the superposition of two contributions to IC that decrease monotonically with L and are damped at lengths about the coherence length of the normal metal. It has been shown that the effective control over the magnitude and sign of IC of the structure is achieved at a small deflection of the vectors M1, 2 from the antiferromagnetic (M1 ↑↓ M2) configuration.