Exchange-biasing topological charges by antiferromagnetism

Qing Lin He; Gen Yin; Alexander J Grutter; Lei Pan; Xiaoyu Che; Guoqiang Yu; Dustin A Gilbert; Steven M Disseler; Yizhou Liu; Padraic Shafer; Bin Zhang; Yingying Wu; Brian J Kirby; Elke Arenholz; Roger K Lake; Xiaodong Han; Kang L Wang

doi:10.1038/s41467-018-05166-9

Exchange-biasing topological charges by antiferromagnetism

Nat Commun. 2018 Jul 17;9(1):2767. doi: 10.1038/s41467-018-05166-9.

Authors

Qing Lin He^{1

2}, Gen Yin³, Alexander J Grutter⁴, Lei Pan³, Xiaoyu Che³, Guoqiang Yu³, Dustin A Gilbert⁴, Steven M Disseler⁴, Yizhou Liu⁵, Padraic Shafer⁶, Bin Zhang⁷, Yingying Wu³, Brian J Kirby⁴, Elke Arenholz⁶, Roger K Lake⁵, Xiaodong Han⁷, Kang L Wang⁸

Affiliations

¹ Department of Electrical and Computer Engineering, Department of Physics and Astronomy, Department of Materials Science and Engineering, University of California, Los Angeles, CA, 90095, USA. qlhe@pku.edu.cn.
² International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, China. qlhe@pku.edu.cn.
³ Department of Electrical and Computer Engineering, Department of Physics and Astronomy, Department of Materials Science and Engineering, University of California, Los Angeles, CA, 90095, USA.
⁴ NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD, 20899-6102, USA.
⁵ Department of Electrical and Computer Engineering, University of California, Riverside, CA, 92521-0204, USA.
⁶ Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
⁷ Beijing Key Lab of Microstructure and Property of Advanced Materials, Beijing University of Technology, Beijing, 100124, China.
⁸ Department of Electrical and Computer Engineering, Department of Physics and Astronomy, Department of Materials Science and Engineering, University of California, Los Angeles, CA, 90095, USA. wang@ee.ucla.edu.

Abstract

Geometric Hall effect is induced by the emergent gauge field experienced by the carriers adiabatically passing through certain real-space topological spin textures, which is a probe to non-trivial spin textures, such as magnetic skyrmions. We report experimental indications of spin-texture topological charges induced in heterostructures of a topological insulator (Bi,Sb)₂Te₃ coupled to an antiferromagnet MnTe. Through a seeding effect, the pinned spins at the interface leads to a tunable modification of the averaged real-space topological charge. This effect experimentally manifests as a modification of the field-dependent geometric Hall effect when the system is field-cooled along different directions. This heterostructure represents a platform for manipulating magnetic topological transitions using antiferromagnetic order.

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.