Xu Zhiming, Duan Wenhui, Xu Yong
State Key Laboratory of Low Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing100084, China.
Tencent Quantum Laboratory, Tencent, Shenzhen, Guangdong518057, China.
Nano Lett. 2023 Jan 11;23(1):305-311. doi: 10.1021/acs.nanolett.2c04369. Epub 2022 Dec 20.
Finding guiding principles to optimize properties of quantum anomalous Hall (QAH) insulators is of pivotal importance to fundamental science and applications. Here, we build a first-principles QAH material database of chirality and band gap, explore microscopic mechanisms determining the QAH material properties, and obtain a general physical picture that can help researchers comprehensively understand the QAH data. Our results reveal that the usually neglected Coulomb exchange is unexpectedly strong in a large class of QAH materials, which is the key to resolve experimental puzzles. Moreover, we identify simple indicators for property evaluation and suggest material design strategies to control QAH chirality and gap by tuning cooperative or competing contributions via magnetic codoping, heterostructuring, spin-orbit proximity, etc. The work is valuable to future research of magnetic topological physics and materials.
寻找优化量子反常霍尔（QAH）绝缘体性质的指导原则对基础科学和应用至关重要。在此，我们构建了一个关于手性和带隙的第一性原理QAH材料数据库，探索决定QAH材料性质的微观机制，并获得一个能帮助研究人员全面理解QAH数据的通用物理图景。我们的结果表明，通常被忽视的库仑交换在一大类QAH材料中出人意料地强，这是解决实验难题的关键。此外，我们确定了用于性质评估的简单指标，并提出了通过磁共掺杂、异质结构、自旋轨道 proximity 等方式调节协同或竞争贡献来控制QAH手性和带隙的材料设计策略。这项工作对磁性拓扑物理和材料的未来研究具有重要价值。
