We report transport studies of hybrid Josephson junctions based on semiconducting InAs nanowires with fully overlapping epitaxial ferromagnetic insulator EuS and superconducting Al partial shells. Current-biased measurements reveal a hysteretic superconducting window with a sizable supercurrent near the coercive field of the ferromagnetic insulator, accompanied by multiple Andreev reflections. Tunneling spectroscopy shows a superconducting gap characterized by three peaks, which we attribute to tunneling between exchange-split superconductors. A theoretical model reproduces the observed features and indicates that spin mixing, driven by sizable spin-orbit coupling, is essential to their formation. Our results demonstrate proximity-induced superconductivity through a ferromagnetic insulator and establish a new platform for exploring spin-triplet pairing.
@article{arxiv.2506.08247,
title = {Spin-split superconductivity in spin-orbit coupled hybrid nanowires with ferromagnetic barriers},
author = {J. Zhao and A. Mazanik and D. Razmadze and Y. Liu and P. Krogstrup and F. S. Bergeret and S. Vaitiekėnas},
journal= {arXiv preprint arXiv:2506.08247},
year = {2026}
}