The spin valve device based on asymmetrical ferromagnet-superconductor trilayer in an external magnetic field

We theoretically explore superconducting proximity effect for the three-layered ferromagnet/superconductor (FS) heterostructures. We consider the boundary value problem for the Usadel-like equations in the case of so-called "dirty" limit. The different mutual orientations of the F layers magnetizations are examined in presence of the external magnetic field. The results of numerical calculations for critical temperature T_c at various parameters of FS structures are presented. The appearance of solitary superconductivity is predicted for the F₁F₂S system. We also discuss possible spin valve applications for F₁F₂S trilayers.