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arXiv · 1601.06045

Long-range supercurrents induced by the interference effect of opposite-spin triplet state in clean superconductor-ferromagnet structures

Hao Meng·Jiansheng Wu·Xiuqiang Wu·Mengyuan Ren·Yajie Ren
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Abstract

By now it is known that in an s-wave superconductor-ferromagnet-superconductor ($SFS$) structure the supercurrent induced by spin singlet pairs can only transmit a short distance of the order of magnetic coherence length. The long-range supercurrent, taking place on the length scale of the normal metal coherence length, will be maintained by equal-spin triplet pairs, which can be generated by magnetic inhomogeneities in the system. In this paper, we show an unusual long-range supercurrent, which can take place in clean $SF_1F_2S$ junction with non-parallel orientation of magnetic moments. The mechanism behind the enhancement of Josephson current is provided by the interference of the opposite-spin triplet states derived from $S/F_1$ and $F_2/S$ interfaces when both ferromagnetic layers have the same values of the length and exchange field. This finds can provide a natural explanation for recent experiment [Robinson et al., Phys. Rev. Lett. 104, 207001 (2010)].

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Hao Meng, Jiansheng Wu, Xiuqiang Wu, Mengyuan Ren, Yajie Ren. 2016-01-22. Long-range supercurrents induced by the interference effect of opposite-spin triplet state in clean superconductor-ferromagnet structures. https://arxiv.org/abs/1601.06045

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