论文标题
$ a $ ti $ x $类中的大范围量子异常霍尔绝缘子
Large-Gap Quantum Anomalous Hall Insulators in $A$Ti$X$ Class
论文作者
论文摘要
从理论上讲，我们建议单层$ a $ ti $ x $家族（KTISB，KTIBI，RBTISB，SRTISN）是大间隙量子异常霍尔绝缘子的潜在候选者，具有高CHERN编号$ \ Mathcal $ \ Mathcal {C C} = 2 $。这些材料中的拓扑和磁性均来自Ti的$ 3D $ - 轨道。我们通过对称分析构建紧密结合模型，以揭示拓扑的起源。值得注意的是，与传统的$ S $ -D $ band倒置截然不同，在这里，拓扑频段倒置在$ 3D $轨道范围内是由于水晶场和电子跳跃，而旋转轨道耦合仅在Fermi级别散发出Dirac Cone的差距。这里的$ 3D $轨道的一般物理学适用于大型过渡金属化合物，其空间群$ p4/nmm $或$ p $ -4200万美元及其子组。
We theoretically propose that the monolayer $A$Ti$X$ family (KTiSb, KTiBi, RbTiSb, SrTiSn) are potential candidates for large-gap quantum anomalous Hall insulators with high Chern number $\mathcal{C}=2$. Both of the topology and magnetism in these materials are from $3d$-orbitals of Ti. We construct the tight-binding model with symmetry analysis to reveal the origin of topology. Remarkably, quite different from the conventional $s$-$d$ band inversion, here the topological band inversion within $3d$ orbitals is due to the crystal field and electron hopping, while spin-orbit coupling only trivially gaps out the Dirac cone at Fermi level. The general physics from the $3d$ orbitals here applies to a large class of transition metal compounds with the space group $P4/nmm$ or $P$-$42m$ and their subgroups.
