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VOLUME 91 (2010) | ISSUE 6 |
PAGE 329
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Superconducting triplet spin valve
Ya. V. Fominov+, A. A. Golubov *, T. Yu. Karminskaya, M. Yu. Kupriyanov, R. G. Deminov, L. R. Tagirov
+L.D. Landau Institute for Theoretical Physics RAS, 119334 Moscow, Russia *Faculty of Science and Technology and MESA+ Institute of Nanotechnology, University of Twente, 7500 AE Enschede, The Netherlands Nuclear Physics Institute, Moscow State University, 119992 Moscow, Russia Physics Faculty, Kazan State University, 420008 Kazan, Russia
Abstract
We study the critical temperature Tc of SFF trilayers (S is a
singlet superconductor, F is a ferromagnetic metal), where the long-range
triplet superconducting component is generated at noncollinear magnetizations
of the F layers. We demonstrate that Tc can be a nonmonotonic function of
the angle α between the magnetizations of the two F layers. The
minimum is achieved at an intermediate α, lying between the parallel
(P, α=0) and antiparallel (AP, α=π) cases. This implies a
possibility of a «triplet» spin-valve effect: at temperatures above the
minimum but below and ,
the system is superconducting only in the vicinity of the collinear
orientations. At certain parameters, we predict a reentrant Tc(α)
behavior. At the same time, considering only the P and AP orientations, we
find that both the «standard» () and
«inverse» () switching effects are
possible depending on parameters of the system.
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