Large Superconducting Spin Valve Effect and Ultrasmall Exchange Splitting in Epitaxial Rare-Earth-Niobium Trilayers.
Phys Rev Lett
American Physical Society (APS)
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Gu, Y., Halász, G. B., Robinson, J., & Blamire, M. (2015). Large Superconducting Spin Valve Effect and Ultrasmall Exchange Splitting in Epitaxial Rare-Earth-Niobium Trilayers.. Phys Rev Lett, 115 067201. https://doi.org/10.1103/PhysRevLett.115.067201
Epitaxial Ho/Nb/Ho and Dy/Nb/Dy superconducting spin valves show a reversible change in the zero-field critical temperature (ΔT(c0)) of ∼400 mK and an infinite magnetoresistance on changing the relative magnetization of the Ho or Dy layers. Unlike transition-metal superconducting spin valves, which show much smaller ΔT(c0) values, our results can be quantitatively modeled. However, the fits require an extraordinarily low induced exchange splitting which is dramatically lower than known values for rare-earth Fermi-level electrons, implying that new models for the magnetic proximity effect may be required.
This work is partially supported by ERC AiG “Superspin”. Yuanzhou Gu acknowledges financial support from King’s College, Cambridge.
External DOI: https://doi.org/10.1103/PhysRevLett.115.067201
This record's URL: https://www.repository.cam.ac.uk/handle/1810/248876