Jiang Jue, Xiao Di, Wang Fei, Shin Jae-Ho, Andreoli Domenico, Zhang Jianxiao, Xiao Run, Zhao Yi-Fan, Kayyalha Morteza, Zhang Ling, Wang Ke, Zang Jiadong, Liu Chaoxing, Samarth Nitin, Chan Moses H W, Chang Cui-Zu
Department of Physics, The Pennsylvania State University, University Park, PA, USA.
Department of Physics, University of New Hampshire, Durham, NH, USA.
Nat Mater. 2020 Jul;19(7):732-737. doi: 10.1038/s41563-020-0605-z. Epub 2020 Feb 3.
The quantum anomalous Hall (QAH) effect is a consequence of non-zero Berry curvature in momentum space. The QAH insulator harbours dissipation-free chiral edge states in the absence of an external magnetic field. However, the topological Hall (TH) effect, a hallmark of chiral spin textures, is a consequence of real-space Berry curvature. Here, by inserting a topological insulator (TI) layer between two magnetic TI layers, we realized the concurrence of the TH effect and the QAH effect through electric-field gating. The TH effect is probed by bulk carriers, whereas the QAH effect is characterized by chiral edge states. The appearance of the TH effect in the QAH insulating regime is a consequence of chiral magnetic domain walls that result from the gate-induced Dzyaloshinskii-Moriya interaction and occurs during the magnetization reversal process in the magnetic TI sandwich samples. The coexistence of chiral edge states and chiral spin textures provides a platform for proof-of-concept dissipationless spin-textured spintronic applications.
量子反常霍尔（QAH）效应是动量空间中非零贝里曲率的结果。QAH绝缘体在没有外部磁场的情况下具有无耗散的手性边缘态。然而，拓扑霍尔（TH）效应作为手性自旋纹理的一个标志，是实空间贝里曲率的结果。在这里，通过在两个磁性拓扑绝缘体（TI）层之间插入一个拓扑绝缘体层，我们通过电场门控实现了TH效应和QAH效应的同时出现。TH效应由体内载流子探测，而QAH效应则由手性边缘态表征。在QAH绝缘区域中TH效应的出现是由门控诱导的Dzyaloshinskii-Moriya相互作用导致的手性磁畴壁的结果，并且发生在磁性TI三明治样品的磁化反转过程中。手性边缘态和手性自旋纹理的共存为概念验证的无耗散自旋纹理自旋电子学应用提供了一个平台。
