Critical spin fluctuation mechanism for the spin Hall effect
ORAL
Abstract
We propose mechanisms for the spin Hall effect in metallic systems arising from the coupling between conduction electrons and local magnetic moments that are dynamically fluctuating. We consider a microscopic model proposed by Kondo [1] for the coupling between electrons and local moments and describe the fluctuation of local moments using the self-consistent renormalization method by Moriya [2]. Both a side-jump-type mechanism and a skew-scattering-type mechanism naturally arise and give rise to a nontrivial temperature dependence in the spin Hall conductivity. This leads to the enhancement in the spin Hall conductivity at non-zero temperatures near the ferromagnetic instability [3]. The proposed mechanisms could be observed in 4d or 5d metallic compounds.
[1] J. Kondo, Prog. Theor. Phys.27, 772 (1962).
[2] T. Moriya, Spin Fluctuations in Itinerant Electron Magnetism, Solid-State Sciences 56 (Springer-Verlag, 1985).
[3] S. Okamoto, T. Egami, and N. Nagaosa, arXiv:1905.10929 (to be published).
[1] J. Kondo, Prog. Theor. Phys.27, 772 (1962).
[2] T. Moriya, Spin Fluctuations in Itinerant Electron Magnetism, Solid-State Sciences 56 (Springer-Verlag, 1985).
[3] S. Okamoto, T. Egami, and N. Nagaosa, arXiv:1905.10929 (to be published).
*The research by S.O. and T.E. is supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division. N.N. was supported by JST CREST Grant Number JPMJCR1874 and JPMJCR16F1, Japan, and JSPSKAKENHI Grant numbers 18H03676 and 26103006.
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Presenters
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Satoshi Okamoto
- Oak Ridge National Lab
- Materials Science and Technology Division, Oak Ridge National Laboratory
- University of Tennessee, Knoxville
- Oak Ridge National Laboratory