Critical current in SFIFS junctions
A. A. Golubov+, M. Yu. Kupriyanov* 1), Ya. V. Fominov
+ Department of Applied Physics, University of Twente, 7500 AE, Enschede, The Netherlands * Nuclear Physics Institute, M. V. Lomonosov Moscow State University, 119899 Moscow, Russia L. D. Landau Institute for Theoretical Physics RAS, 117940 Moscow, Russia
PACS: 74.50.+r, 74.80.Dm, 75.30.Et
Abstract
Quantitative theory of the Josephson effect in SFIFS junctions (S
denotes bulk superconductor, F - metallic ferromagnet, I - insulating
barrier) is presented in the dirty limit. Fully self-consistent numerical
procedure is employed to solve the Usadel equations at arbitrary values of
the F-layers thicknesses, magnetizations, and interface parameters. In the
case of antiparallel ferromagnets magnetizations the effect of the critical
current Ic enhancement by the exchange energy H is observed, while in
the case of parallel magnetizations the junction exhibits the transition to
the π-state. In the limit of thin F-layers, we study these peculiarities
of the critical current analytically and explain them qualitatively; the
scenario of the 0-π transition in our case differs from those studied
before. The effect of switching between 0 and π states by changing the
F-layers mutual orientation is demonstrated.
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