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Odd triplet superconductivity in a superconductor/ferromagnet structure with a spiral magnetic structure

A. F. Volkov·A. Anishchanka·K. B Efetov
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Abstract

We analyze a superconductor-ferromagnet (S/F) system with a spiral magnetic structure in the ferromagnet F for a weak and strong exchange field. The long-range triplet component (LRTC) penetrating into the ferromagnet over a long distance is calculated for both cases. In the dirty limit (or weak ferromagnetism) we study the LRTC for conical ferromagnets. Its spatial dependence undergoes a qualitative change as a function of the cone angle θ. At small angles the LRTC decays in the ferromagnet exponentially in a monotonic way. If the angle θexceeds a certain value, the exponential decay of the LRTC is accompanied by oscillations with a period that depends on θ. This oscillatory behaviour leads to a similar dependence of the Josephson critical current in SFS junctions on the thickness of the F layer. In the case of a strong ferromagnet the LRTC decays over the length which is determined by the wave vector of the magnetic spiral and by the exchange field.

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A. F. Volkov, A. Anishchanka, K. B Efetov. 2006-03-06. Odd triplet superconductivity in a superconductor/ferromagnet structure with a spiral magnetic structure. https://doi.org/10.1103/physrevb.73.104412

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