Josephson effect and triplet pairing in SFFS junctions

Abstract

We study the Josephson effect and pairing correlations in SFFS junctions that consist of conventional superconductors (S) connected through two metallic monodomain ferromagnets (F) with transparent and spin-inactive interfaces. We solve the Eilenberger equations for arbitrary relative orientation of magnetizations of the two F layers in the clean limit, and calculate spatial variation of pair amplitudes, singlet fs, and odd-frequency triplet ft0 and ft1, with 0 and ±1 spin projections, as well as the Josephson current. We find that for the angle 0 < α < π between in-plane magnetizations, both spin singlet and triplet pair amplitudes in F layers decay in the same oscillatory manner with distance from the FS interfaces. The computed triplet amplitude ft1 penetrates into the superconductors and monotonically decays over the superconducting coherence length, which is the same distance as the singlet amplitudes fs saturates to the bulk value. © 2009 American Institute of Physics.