Li Jie, Wu Ruqian
School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China.
Department of Physics and Astronomy, University of California, Irvine, California 92697-4575, United States.
Nano Lett. 2023 Mar 22;23(6):2173-2178. doi: 10.1021/acs.nanolett.2c04708. Epub 2023 Mar 1.
The realization and control of the quantum anomalous Hall (QAH) effect are highly desirable for the development of spintronic and quantum devices. In this work, we propose a van der Waals (vdW) heterostructure of ultrathin MnBiSe and BiSe layers and demonstrate that it is an excellent tunable QAH platform by using model Hamiltonian and density functional theory simulations. Its band gap closes and reopens as external electric field increases, manifesting a novel topological phase transition with an electric field of ∼0.06 V/Å. This heterostructure has other major advantageous, such as large topological band gap, perpendicular magnetization, and strong ferromagnetic ordering. Our work provides clear physical insights and suggests a new strategy for experimental realization and control of the QAH effect in real materials.
对于自旋电子学和量子器件的发展而言，量子反常霍尔（QAH）效应的实现与控制是极为可取的。在这项工作中，我们提出了一种由超薄MnBiSe和BiSe层构成的范德华（vdW）异质结构，并通过模型哈密顿量和密度泛函理论模拟证明它是一个出色的可调控QAH平台。随着外部电场增加，其带隙关闭并重新打开，在约0.06 V/Å的电场下表现出一种新型拓扑相变。这种异质结构还有其他主要优势，如大的拓扑带隙、垂直磁化和强铁磁有序。我们的工作提供了清晰的物理见解，并为在实际材料中实验实现和控制QAH效应提出了一种新策略。
