Wang Fei, Wang Xuepeng, Zhao Yi-Fan, Xiao Di, Zhou Ling-Jie, Liu Wei, Zhang Zhidong, Zhao Weiwei, Chan Moses H W, Samarth Nitin, Liu Chaoxing, Zhang Haijun, Chang Cui-Zu
Department of Physics, The Pennsylvania State University, University Park, PA, 16802, USA.
Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 110016, Shenyang, China.
Nat Commun. 2021 Jan 4;12(1):79. doi: 10.1038/s41467-020-20349-z.
The Berry phase picture provides important insights into the electronic properties of condensed matter systems. The intrinsic anomalous Hall (AH) effect can be understood as the consequence of non-zero Berry curvature in momentum space. Here, we fabricate TI/magnetic TI heterostructures and find that the sign of the AH effect in the magnetic TI layer can be changed from being positive to negative with increasing the thickness of the top TI layer. Our first-principles calculations show that the built-in electric fields at the TI/magnetic TI interface influence the band structure of the magnetic TI layer, and thus lead to a reconstruction of the Berry curvature in the heterostructure samples. Based on the interface-induced AH effect with a negative sign in TI/V-doped TI bilayer structures, we create an artificial "topological Hall effect"-like feature in the Hall trace of the V-doped TI/TI/Cr-doped TI sandwich heterostructures. Our study provides a new route to create the Berry curvature change in magnetic topological materials that may lead to potential technological applications.
贝里相位图为凝聚态物质系统的电子性质提供了重要见解。本征反常霍尔（AH）效应可被理解为动量空间中非零贝里曲率的结果。在此，我们制备了TI/磁性TI异质结构，并发现随着顶部TI层厚度的增加，磁性TI层中AH效应的符号可从正变为负。我们的第一性原理计算表明，TI/磁性TI界面处的内建电场会影响磁性TI层的能带结构，进而导致异质结构样品中贝里曲率的重构。基于TI/V掺杂TI双层结构中具有负号的界面诱导AH效应，我们在V掺杂TI/TI/Cr掺杂TI三明治异质结构的霍尔迹线中创造了一种类似人工“拓扑霍尔效应”的特征。我们的研究为在磁性拓扑材料中产生贝里曲率变化提供了一条新途径，这可能会带来潜在的技术应用。
