反強磁性体におけるスピントランスファートルク; その効率と定量化法 Spin-transfer torques in antiferromagnetic textures; Efficiency and quantification method

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Abstract

著者所属: 日本原子力研究開発機構(JAEA)

We formulate a theory of spin-transfer torques in antiferromagnets, which covers the small to large limits of the exchange coupling energy relative to the kinetic energy of the inter-sublattice electron dynamics. Our theory suggests a natural definition of the efficiency of spin-transfer torques in antiferromagnets in terms of well-defined material parameters, revealing that the charge current couples predominantly to the antiferromagnetic order parameter and the sublattice-canting moment in, respectively, the limits of large and small exchange coupling. The effects can be quantified by analyzing the antiferromagnetic spin-wave dispersions in the presence of charge current: in the limit of large exchange coupling the spin-wave Doppler shift always occurs, whereas, in the opposite limit, the only spin-wave modes to react to the charge current are ones that carry a pronounced sublattice-canting moment. The findings offer a framework for understanding and designing spin-transfer torques in antiferromagnets belonging to different classes of sublattice structures such as, e.g., bipartite and layered antiferromagnets.

Journal

  • Physical Review B

    Physical Review B 94(5), 054409\_1-054409\_8, 2016-08

    American Physical Society

Codes

  • NII Article ID (NAID)
    120006503515
  • Text Lang
    ENG
  • Article Type
    journal article
  • ISSN
    2469-9950
  • Data Source
    IR 
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