The peculiarities of the operation of the superconducting spin valve
Review of our recent results concerning the spin valve effect are presented. Using the spin switch design F1/F2/S proposed theoretically that comprises a ferromagnetic bilayer (F1/F2) as a ferromagnetic component, and an ordinary superconductor (S) as the second interface component, we have realized for the first time a full spin switch effect for the superconducting current. For CoOx/Fe1/Cu/Fe2/In multilayered systems with varying Fe2-layer thickness we observed the sign-changing oscillating behavior of the spin valve effect ΔTc = TcAP - TcP (here TcAP and TcP are the superconducting transition temperatures for antiparallel and parallel orientations of magnetizations of the F1 and F2 layers, respectively). We have also studied the angular dependence of Tc for the spin valve system CoOx/Fe1/Cu/Fe2/Pb. We found that this dependence is nonmonotonic when passing from the parallel to the antiparallel case of mutual orientation of magnetizations of the Fe1 and Fe2 layers and reveals a distinct minimum near the orthogonal configuration. The analysis of the data in the framework of the superconducting triplet spin valve theory gives direct evidence for the long-range triplet superconductivity arising due to noncollinearity of the two magnetizations.