Niu Chengwang, Hanke Jan-Philipp, Buhl Patrick M, Zhang Hongbin, Plucinski Lukasz, Wortmann Daniel, Blügel Stefan, Bihlmayer Gustav, Mokrousov Yuriy
School of Physics, State Key Laboratory of Crystal Materials, Shandong University, 250100, Jinan, China.
Peter Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich and JARA, 52425, Jülich, Germany.
Nat Commun. 2019 Jul 18;10(1):3179. doi: 10.1038/s41467-019-10930-6.
The concepts of Weyl fermions and topological semimetals emerging in three-dimensional momentum space are extensively explored owing to the vast variety of exotic properties that they give rise to. On the other hand, very little is known about semimetallic states emerging in two-dimensional magnetic materials, which present the foundation for both present and future information technology. Here, we demonstrate that including the magnetization direction into the topological analysis allows for a natural classification of topological semimetallic states that manifest in two-dimensional ferromagnets as a result of the interplay between spin-orbit and exchange interactions. We explore the emergence and stability of such mixed topological semimetals in realistic materials, and point out the perspectives of mixed topological states for current-induced orbital magnetism and current-induced domain wall motion. Our findings pave the way to understanding, engineering and utilizing topological semimetallic states in two-dimensional spin-orbit ferromagnets.
由于三维动量空间中出现的外尔费米子和拓扑半金属概念会产生各种各样的奇异特性，因此对它们进行了广泛的探索。另一方面，对于二维磁性材料中出现的半金属态，人们了解甚少，而二维磁性材料是当前和未来信息技术的基础。在此，我们证明，将磁化方向纳入拓扑分析，可以对拓扑半金属态进行自然分类，这些态由于自旋轨道和交换相互作用之间的相互作用，在二维铁磁体中表现出来。我们探索了这种混合拓扑半金属在实际材料中的出现和稳定性，并指出了混合拓扑态在电流诱导轨道磁性和电流诱导畴壁运动方面的前景。我们的研究结果为理解、设计和利用二维自旋轨道铁磁体中的拓扑半金属态铺平了道路。
