We report the observation of spin transport through antiferromagnetic insulators using spin pumping driven by short-wavelength magnons. The short-wavelength magnons are excited by parametric pumping in a Pt/NiO/Y3Fe5O12 trilayer. The parametrically excited magnons in the Y3Fe5O12 layer inject a spin current into the NiO layer, which is detected electrically using the inverse spin Hall effect in the Pt layer. We found that the spin-pumping efficiency of the parametrically excited magnons in the Pt/NiO/Y3Fe5O12 film is nearly an order of magnitude smaller than that in the Pt/Y3Fe5O12 film. The suppression of the parametric spin-pumping efficiency induced by inserting the NiO layer is comparable to that of the FMR spin-pumping efficiency. We further found that the suppression of the spin-pumping efficiency due to the NiO insertion for the dipole-exchange magnons with the wave number of k∼103-104cm-1 is more significant than that for the exchange magnons with k∼105cm-1. This difference is attributed to two-magnon scattering and spin pinning due to antiferromagnetic grains in the NiO layer. These results provide insight into the understanding of the spin pumping into antiferromagnetic insulators.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics