Ding Jinjun, Liu Chuanpu, Kalappattil Vijaysankar, Zhang Yuejie, Mosendz Oleksandr, Erugu Uppalaiah, Yu Rui, Tian Jifa, DeMann August, Field Stuart B, Yang Xiaofei, Ding Haifeng, Tang Jinke, Terris Bruce, Fert Albert, Chen Hua, Wu Mingzhong
Department of Physics, Colorado State University, Fort Collins, CO, 80523, USA.
School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, Hubei, 430074, China.
Adv Mater. 2021 Jun;33(23):e2005909. doi: 10.1002/adma.202005909. Epub 2021 May 3.
Recent experiments show that topological surface states (TSS) in topological insulators (TI) can be exploited to manipulate magnetic ordering in ferromagnets. In principle, TSS should also exist for other topological materials, but it remains unexplored as to whether such states can also be utilized to manipulate ferromagnets. Herein, current-induced magnetization switching enabled by TSS in a non-TI topological material, namely, a topological Dirac semimetal α-Sn, is reported. The experiments use an α-Sn/Ag/CoFeB trilayer structure. The magnetization in the CoFeB layer can be switched by a charge current at room temperature, without an external magnetic field. The data show that the switching is driven by the TSS of the α-Sn layer, rather than spin-orbit coupling in the bulk of the α-Sn layer or current-produced heating. The switching efficiency is as high as in TI systems. This shows that the topological Dirac semimetal α-Sn is as promising as TI materials in terms of spintronic applications.
近期实验表明，拓扑绝缘体（TI）中的拓扑表面态（TSS）可用于操控铁磁体中的磁有序。原则上，其他拓扑材料中也应存在TSS，但此类状态是否也能用于操控铁磁体仍有待探索。在此，报道了在非TI拓扑材料即拓扑狄拉克半金属α-Sn中由TSS实现的电流诱导磁化翻转。实验采用α-Sn/Ag/CoFeB三层结构。在室温下，无需外部磁场，CoFeB层中的磁化可通过充电电流进行翻转。数据表明，翻转是由α-Sn层的TSS驱动的，而非α-Sn层体材料中的自旋轨道耦合或电流产生的热效应。翻转效率与TI系统中的一样高。这表明，在自旋电子学应用方面，拓扑狄拉克半金属α-Sn与TI材料一样具有前景。
