2009/07/15 by Klaus Halterman, Oriol T. Valls
Physics and Astronomy · #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.80.104502
published as Phys. Rev B 80, 104502 (2009) · 14 pages including figures (some compressed). Good quality figures available from authors
arxiv created 2009/07/15 · arxiv updated 2015/05/13
We study triplet pairing correlations induced in an SFS trilayer (where F is a ferromagnet and S an ordinary s-wave superconductor) by spin flip scattering at the interfaces. We derive and solve self consistently the appropriate Bogoliubov-de Gennes equations in the clean limit. We find that the spin flip scattering generates m=± 1 triplet correlations, odd in time. We study the general spatial behavior of these and of m=0 correlations as a function of position and of spin-flip strength, Hspin. We concentrate on the case where the ferromagnet is half-metallic. We find that for certain values of Hspin, the triplet correlations pervade the magnetic layer and can penetrate deeply into the superconductor. The behavior we find depends very strongly on whether the singlet order parameter is in the 0 or π state, which must in turn be determined self-consistently. We also present results for the density of states (DOS) and for the local magnetization, which, due to spin-flip processes, is not in general aligned with the magnetization of the half metal, and near the interfaces, rotates as a function of position and Hspin. The average DOS in both F and S is shown to exhibit various subgap bound states positioned at energies that depend strongly on the particular junction state and the spin