Domain walls and long-range triplet correlations in SFS Josephson junctions

We study the contribution of domain walls to the Josephson current through a ferromagnetic metal both in clean and diffusive limits. Our consideration of these limits is based on the quasiclassical version of the Bogoliubov-de Gennes equations and the Usadel theory, correspondingly. In the clean limit, the domain walls connecting superconducting leads are shown to be responsible for strong enhancement of the Josephson current, even for a domain structure with collinear magnetic moments. In the dirty limit, a noticeable increase in the critical current appears only for a system with noncollinear magnetic moments. We demonstrate that a thin domain wall in this case may serve as an efficient source of the long-range triplet proximity effect.