연구 Highlight

Emergent Topological Hall Effect from Exchange Coupling in Ferromagnetic Cr2Te3/Noncoplanar Antiferromagnetic Cr2Se3 Bilayers

  • 저자명

    Jae Ho Jeon, Hong Ryeol Na, Heeju Kim, Sunghun Lee, Sehwan Song, Jiwoong Kim, Sungkyun Park, Jeong Kim, Hwayong Noh, Gunn Kim, Sahng-Kyoon Jerng,* and Seung-Hyun Chun

  • 저널명

    ACS Nano

  • 게재권/집

    16(2022)

  • 페이지

    8974~8982

  • 발표일

    2022-05-27

  • URLhttps://doi.org/10.1021/acsnano.2c00025
The topological Hall effect has been observed in magnetic materials of complex spin structures or bilayers of trivial magnets and strong spin−orbit-coupled systems. In view of current attention on dissipationless
topological electronics, the occurrence of the topological Hall effect in new systems or by an unexpected mechanism is fascinating. Here, we report a robust topological Hall effect generated in bilayers of a ferromagnet and a noncoplanar antiferromagnet, from the interfacial Dzyaloshinskii−Moriya interaction due to the exchange coupling of magnetic layers. Molecular beam epitaxy has been utilized to fabricate heterostructures of a
ferromagnetic metal Cr2Te3 and a noncoplanar antiferromagnet Cr2Se3. A significant topological Hall effect at low temperature implies the development of nontrivial spin chirality, and density functional theory calculations explain the correlation of the Dzyaloshinskii−Moriya interaction increase and inversion symmetry breaking at the interface. The presence of noncoplanar ordering in the antiferromagnet plays a pivotal role in producing the topological Hall effect. Our results suggest that the exchange coupling in ferromagnet/noncoplanar antiferromagnet bilayers could be an alternative mechanism toward topologically protected magnetic structures.