Large interfacial exchange fields in a thick superconducting film coupled to a spin filter tunnel barrier
Physical Review B: Condensed Matter and Materials Physics
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Pal, A., & Blamire, M. (2015). Large interfacial exchange fields in a thick superconducting film coupled to a spin filter tunnel barrier. Physical Review B: Condensed Matter and Materials Physics, 92 (180510)https://doi.org/10.1103/PhysRevB.92.180510
The differential conductance of NbN/GdN/TiN superconductor / ferromagnetic insulator / normal metal junctions, with a thick NbN layer shows a large zero-field voltage offset interpreted as a spin-filtered Zeeman splitting of the NbN density of states (DOS) by an effective exchange field (H₀) from the GdN. The splitting increases linearly with applied field (H_ext) enabling the relative sign of H₀ and H_ext to be determined. We show that the short NbN coherence length concentrates H₀ at the NbN/GdN interface and eliminates any averaging over the GdN domain structure leading to a large zero-field splitting.
This work was supported by the ERC Advanced Investigator Grant (Superspin).
External DOI: https://doi.org/10.1103/PhysRevB.92.180510
This record's URL: https://www.repository.cam.ac.uk/handle/1810/252867