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arXiv · cond-mat/0102012

Enhancement of the Josephson current by an exchange field in superconductor-ferromagnet structures

F. S. Bergeret·A. F. Volkov·K. B. Efetov
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Abstract

We calculate the dc Josephson current for two superconductor-ferromagnet (S/F) bilayers separated by a thin insulating film. It is demonstrated that the critical Josephson current $I_{c}$ in the junction strongly depends on the relative orientation of the effective exchange field $h$ of the bilayers. We found that in the case of an antiparallel orientation, $I_{c}$ increases at low temperatures with increasing $h$ and at zero temperature has a singularity when $h$ equals the superconducting gap $Δ$. This striking behavior contrasts suppression of the critical current by the magnetic moments aligned in parallel and is an interesting new effect of the interplay between superconductors and ferromagnets.

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F. S. Bergeret, A. F. Volkov, K. B. Efetov. 2001-02-01. Enhancement of the Josephson current by an exchange field in superconductor-ferromagnet structures. https://doi.org/10.1103/physrevlett.86.3140

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