Abstract: When a Superconductor (S) is placed next to a ferromagnet (F), the electrons from the spin-singlet Cooper pairs enter different spin bands and rapidly lose phase coherence over a short length scale. However, it is predicted that in the presence of magnetic inhomogeneities not only spin-singlet but also long range spin-triplet correlations are generated. The symmetry of these long range spin-triplet correlations is different from the spin-triplet correlations found in strontium ruthenate Sr2RuO4 and in heavy fermion intermetallic compounds. The novelty of spin-triplet correlations studied here lies in the fact that they are odd under time reversal. I will talk about our search of proximity-induced triplet correlations in ferromagnetic Josephson junctions. In particular I will focus on our recent experiment on Co-based Josephson junctions [1] that have shown strong evidence of these triplet correlations and will explain the experimental considerations that went into designing the peculiar multilayer used in this work.
[1] T.S. Khaire, M.A. Khasawneh, W.P. Pratt, Jr., and N.O. Birge, Phys. Rev. Lett. 104, 137002 (2010).