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Interfacial Dzyaloshinskii-Moriya interaction in nonmagnetic/noncollinear-antiferromagnetic bilayers

ORAL

Abstract

Dzyaloshinskii-Moriya interaction (DMI), an antisymmetric spin-spin exchange interaction resulting from spatial inversion breaking, plays fundamental roles in a variety of phenomena. The effects of DMI are widely studied in nonmagnetic/magnetic bilayers, where interfacial DMI (i-DMI) arises due to the breaking of inversion symmetry at the interface.

We present our theoretical formulation of the i-DMI for a nonmagnetic/noncollinear-AFM bilayer. Here, noncollinear AFMs refer to frustrated kagome AFMs, such as D019-Mn3Sn [1], that show a triangular magnetic order. In the emerging research field of antiferromagnetic spintronics [2], noncollinear AFMs are expected to play pivotal roles [3]. Recent successes in epitaxial growth of Mn3Sn [4] have propelled studies on noncollinear AFM thin films that are most often attached to some adjacent nonmagnetic films. There lacks, however, a theoretical framework to quantitatively and systematically study physical implications of the i-DMI in such systems.

In this work, we find that the i-DMI provides a sublattice-asymmetric renormalization to the bulk DMI, the latter being present due to the locally-broken inversion symmetry of the hexagonal Kagome lattice structure. As a consequence of this i-DMI, a uniaxial anisotropy for the AFM order parameter with respect to the film normal direction is predicted to emerge. Our analytical predictions are supported by numerical simulations.

Publication: [1] S. Tomiyoshi and Y. Yamaguchi, J. Phys. Soc. Jpn. 51, 2478 (1982).<br>[2] T. Jungwirth et al., Nat. Nanotechnol. 11, 231 (2016); V. Baltz et al., Rev. Mod. Phys. 90, 015005 (2018).<br>[3] S. Nakatsuji et al., Nature 527, 212 (2015); Y. Takeuchi et al., Nat. Mater. 20, 1364 (2021); T. Higo et al., Nature 607, 474 (2022).<br>[4] A. Markou et al., Phys. Rev. Mater. 2, 051001(R) (2018); J. Yoon et al., Appl. Phys. Exp. 13, 013001 (2019).

Presenters

  • Yuta Yamane

    Tohoku University, Japan

Authors

  • Yuta Yamane

    Tohoku University, Japan

  • Yasufumi Araki

    Japan Atomic Energy Agency

  • Shunsuke Fukami

    Tohoku University, Japan