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arXiv · 1810.00218

Giant and anisotropic many-body spin-orbit tunability in a strongly correlated kagome magnet

Jia-Xin Yin·Songtian S. Zhang·Hang Li·Kun Jiang·Guoqing Chang·Bingjing Zhang·Biao Lian·Cheng Xiang·Ilya Belopolski·Hao Zheng·Tyler A. Cochran·Su-Yang Xu·Guang Bian·Kai Liu·Tay-Rong Chang·Hsin Lin·Zhong-Yi Lu·Ziqiang Wang·Shuang Jia·Wenhong Wang·M. Zahid Hasan
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Abstract

Owing to the unusual geometry of kagome lattices-lattices made of corner-sharing triangles-their electrons are useful for studying the physics of frustrated, correlated and topological quantum electronic states. In the presence of strong spin-orbit coupling, the magnetic and electronic structures of kagome lattices are further entangled, which can lead to hitherto unknown spin-orbit phenomena. Here we use a combination of vector-magnetic-field capability and scanning tunnelling microscopy to elucidate the spin-orbit nature of the kagome ferromagnet Fe3Sn2 and explore the associated exotic correlated phenomena. We discover that a many-body electronic state from the kagome lattice couples strongly to the vector field with three-dimensional anisotropy, exhibiting a magnetization-driven giant nematic (two-fold-symmetric) energy shift. Probing the fermionic quasi-particle interference reveals consistent spontaneous nematicity-a clear indication of electron correlation-and vector magnetization is capable of altering this state, thus controlling the many-body electronic symmetry. These spin-driven giant electronic responses go well beyond Zeeman physics and point to the realization of an underlying correlated magnetic topological phase. The tunability of this kagome magnet reveals a strong interplay between an externally applied field, electronic excitations and nematicity, providing new ways of controlling spin-orbit properties and exploring emergent phenomena in topological or quantum materials.

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Jia-Xin Yin, Songtian S. Zhang, Hang Li, Kun Jiang, Guoqing Chang, Bingjing Zhang, Biao Lian, Cheng Xiang, Ilya Belopolski, Hao Zheng, Tyler A. Cochran, Su-Yang Xu, Guang Bian, Kai Liu, Tay-Rong Chang, Hsin Lin, Zhong-Yi Lu, Ziqiang Wang, Shuang Jia, Wenhong Wang, M. Zahid Hasan. 2018-09-29. Giant and anisotropic many-body spin-orbit tunability in a strongly correlated kagome magnet. https://doi.org/10.1038/s41586-018-0502-7

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