Xu Gang, Lian Biao, Zhang Shou-Cheng
Department of Physics, McCullough Building, Stanford University, Stanford, California 94305-4045, USA.
Phys Rev Lett. 2015 Oct 30;115(18):186802. doi: 10.1103/PhysRevLett.115.186802. Epub 2015 Oct 27.
In a kagome lattice, the time reversal symmetry can be broken by a staggered magnetic flux emerging from ferromagnetic ordering and intrinsic spin-orbit coupling, leading to several well-separated nontrivial Chern bands and intrinsic quantum anomalous Hall effect. Based on this idea and ab initio calculations, we propose the realization of the intrinsic quantum anomalous Hall effect in the single layer Cs_{2}Mn_{3}F_{12} kagome lattice and on the (001) surface of a Cs_{2}LiMn_{3}F_{12} single crystal by modifying the carrier coverage on it, where the band gap is around 20 meV. Moreover, a simplified tight binding model based on the in-plane ddσ antibonding states is constructed to understand the topological band structures of the system.
在一个 Kagome 晶格中,时间反演对称性可被源自铁磁序和本征自旋轨道耦合的交错磁通量打破,从而导致几个明显分离的非平凡陈数能带和本征量子反常霍尔效应。基于这一想法和第一性原理计算,我们提出通过改变单层 Cs₂Mn₃F₁₂ Kagome 晶格以及 Cs₂LiMn₃F₁₂ 单晶 (001) 表面上的载流子覆盖度来实现本征量子反常霍尔效应,其带隙约为 20 毫电子伏特。此外,构建了一个基于面内 ddσ 反键态的简化紧束缚模型,以理解该系统的拓扑能带结构。