Abstract
We study the impact of the long range spin-triplet proximity effect on the density of states (DOS) in planar SFFS Josephson junctions that consist of conventional superconductors (S) connected by two metallic monodomain ferromagnets (F and F) with transparent interfaces. We determine the electronic DOS in F layers for arbitrary orientation of the magnetizations using the solutions of Eilenberger equations in the clean limit and for a moderate concentration of impurities in ferromagnets. We find that a fully developed long range proximity effect occurs in Josephson junctions with a highly asymmetric ferromagnetic bilayer. For orthogonal magnetizations, the effect manifests itself as an enhancement in DOS and as a dominant second harmonic in the Josephson current-phase relation. Distinctive variation of DOS in ferromagnets with the angle between magnetizations is experimentally observable by tunneling spectroscopy. This can provide an unambiguous signature of the long range spin-triplet proximity effect.
- Received 19 December 2011
DOI:https://doi.org/10.1103/PhysRevB.85.094517
©2012 American Physical Society