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arXiv · 1912.08587

Observation of the dominant spin-triplet supercurrent in Josephson spin valves with strong Ni ferromagnets

O. M. Kapran·A. Iovan·T. Golod·V. M. Krasnov
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Abstract

We study experimentally nanoscale Josephson junctions and Josephson spin-valves containing strong Ni ferromagnets. We observe that in contrast to junctions, spin valves with the same geometry exhibit anomalous Ic(H) patterns with two peaks separated by a dip. We develop several techniques for in-situ characterization of micromagnetic states in our nano-devices, including magnetoresistance, absolute Josephson fluxometry and First-Order-Reversal-Curves analysis. They reveal a clear correlation of the dip in supercurrent with the antiparallel state of a spin-valve and the peaks with two noncollinear magnetic states, thus providing evidence for generation of spin-triplet superconductivity. A quantitative analysis brings us to a conclusion that the triplet current in out Ni-based spin-valves is approximately three times larger than the conventional singlet supercurrent.

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O. M. Kapran, A. Iovan, T. Golod, V. M. Krasnov. 2019-12-18. Observation of the dominant spin-triplet supercurrent in Josephson spin valves with strong Ni ferromagnets. https://doi.org/10.1103/physrevresearch.2.013167

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