Berlin 2005 – wissenschaftliches Programm

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TT: Tiefe Temperaturen

TT 23: Posters Superconductivity, Solids at Low Temperature

TT 23.37: Poster

Montag, 7. März 2005, 14:00–18:00, Poster TU D

Alternative mechanism of the sign-reversal effect in Superconductor-Ferromagnet-Superconductor Josephson Junctions — •Alexandra Anishchanka¹ and Anatoli Volkov^1,2 — ¹Theoretische Physik III, Ruhr-Universität Bochum, D-44801, Germany — ²Institute of Radioengineering and Electronics of the Russian Academy of Sciences, 103907 Moscow, Russia

We consider a simple model of a multidomain superconductor-ferromagnet-superconductor (SFS) Josephson junction. Sign-alternating magnetization M in domains leads to a spatial modulation of the phase difference φ (x). Due to this modulation the Josephson critical current I_c may have a different sign depending on the ratio of the magnetic flux in a domain, 4π Ma(2d_F), and the magnetic flux quantum. Just this, but not a nonmonotonic dependence of the local critical current density j_c, may be the reason for oscillations of the current I_c as a function of the F layer thickness 2d_F or temperature, observed in experiments.