Long-range proximity effect for opposite-spin pairs in S/F heterostructures under non-equilibrium quasiparticle distribution

I. V. Bobkova; A. M. Bobkov

doi:10.1103/physrevlett.108.197002

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arXiv · 1202.0165

Long-range proximity effect for opposite-spin pairs in S/F heterostructures under non-equilibrium quasiparticle distribution

I. V. Bobkova·A. M. Bobkov

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Abstract

By now it is known that in a singlet superconductor/ferromagnet (S/F) structure the superconducting correlations carried by opposite-spin pairs penetrate into the ferromagnet over a short distance of the order of magnetic coherence length. The long-range proximity effect (LRPE), taking place on the length scale of the normal metal coherence length, can only be maintained by equal-spin pairs, which can be generated by magnetic inhomogeneities in the system. In this work we have predicted a new type of LRPE, which can take place in S/F heterostructures under non-equilibrium conditions. The superconducting correlations in the F region are generated by opposite-spin Cooper pairs and equal-spin pairs are not involved. The possibility for an opposite-spin pair to penetrate into the ferromagnet over a large distance is provided by creation of the proper non-equilibrium quasiparticle distribution there. This leads to a sharp increase (up to a few orders of magnitude) of the critical Josephson current through a S/F/S junction at some values of the voltage controlling the nonequilibrium distribution in the F interlayer.

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I. V. Bobkova, A. M. Bobkov. 2012-02-01. Long-range proximity effect for opposite-spin pairs in S/F heterostructures under non-equilibrium quasiparticle distribution. https://doi.org/10.1103/physrevlett.108.197002

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