Enhanced triplet pairing in magnetic junctions with s-wave superconductors

A common path to Majorana fermions and topologically-protected quantum computing relies on spin-triplet superconductivity[1]. While spin-triplet pairing is elusive in nature and even common spin-triplet candidates, such as Sr2RuO4, could support alternative explanations[2], proximity effects in heterostructures can overcome these limitations. Specifically, a common expectation is that robust spin-triplet superconductivity in magnetic junctions should rely on highly spin-polarized magnets or complex magnetic multilayers[3]. Instead, we predict that the interplay of interfacial spin-orbit coupling and the barrier strength in simple magnetic junctions with s-wave superconductors can lead to nearly complete spin-triplet superconducting proximity effects when magnets have only a small spin polarization[4]. We show that this enhanced spin-triplet regime is characterized by a huge increase in conductance magnetoanisotropy[4-6], orders of magnitude larger than in the normal state.
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[3] M. Eschrig, Phys. Today 64, 43 (2011)
[4] T. Vezin, C. Shen, J. E. Han, I. Zutic, arXiv:1904.10773 (2019)
[5] P. Högl, et al., PRL 115, 116601 (2015)
[6] I. Martnez, et al., arXiv:1812.08090 (2018)