Manifestation of new interference effects in a superconductor-ferromagnet spin valve
| P. V. Leksin, N. N. Garif’yanov, I. A. Garifullin, J. Schumann, V. Kataev, O. G. Schmidt, B. Büchner Phy. Rev. Lett. 106, 067005 (2011) URL PDF |
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| Abstract | |
| Superconductor-ferromagnet (S/F) spin valve effect theories based on the S/F proximity phenomenon assume that the superconducting transition temperature Tc of F1/F2/S or F1/S/F2 trilayers for parallel magnetizations of the F1 and F2 layers (TcP) are smaller than for the antiparallel orientations (TcAP). Here, we report for CoOx/Fe1/Cu/Fe2/In multilayers with varying Fe2-layer thickness the sign-changing oscillating behavior of the spin valve effect ΔTc=TcAP-TcP. We observe the full direct effect with TcAP>TcP for Fe2-layer thickness dFe2<1 nm and the full inverse (TcAP<TcP) effect for dFe2≥1 nm. Interference of Cooper pair wave functions reflected from both surfaces of the Fe2 layer appear as the most probable reason for the observed behavior of ΔTc. |