| Description |
When a superconductor is placed in contact with a ferromagnet, Cooper pairs can cross the interface into the ferromagnet. When they do so, the two electrons from the spin-singlet Cooper pair enter different spin bands and rapidly lose phase coherence over a short length scale. This is called the conventional spin-singlet proximity effect. 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 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 spin-triplet correlations in ferromagnetic Josephson junctions. The generation of these spin-triplet correlations is known to be very sensitive to the presence of magnetic inhomogeneities in the ferromagnet. And once generated, there are several factors that pose difficulty in their long-range propagation. Our major task therefore was to separate the “generation” and “propagation” of the triplet correlations in our system. In this talk I will focus on the considerations that went into modeling a Cobalt-based Josephson junction that has shown a very strong evidence of long-range triplet correlations. [1] .
[1] T.S. Khaire, M.A. Khasawneh, W.P. Pratt, Jr., and N.O. Birge, Phys. Rev. Lett. 104, 137002 (2010).
|