We study the transport properties of nanoscale superconducting (S) devices inwhich two superconducting electrodes are bridged by two parallel ferromagnetic(F) wires, forming an SFFS junction with a separation between the two wiresless than the superconducting coherence length. This allows crossed Andreevreflection to take place. We find that the resistance as a function oftemperature exhibits behavior reminiscent of the re-entrant effect and, at lowtemperatures and excitation energies below the superconducting gap, theresistance corresponding to antiparallel alignment of the magnetization of theferromagnetic wires is higher than that of parallel alignment, in contrast tothe behavior expected from crossed Andreev reflection. We present a model basedon spin-dependent interface scattering that explains this surprising result anddemonstrates the sensitivity of the junction transport properties tointerfacial parameters.
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