论文标题
Kagomé晶格多功能系统中的拓扑平坦乐队
Topological flat bands in a kagomé lattice multiorbital system
论文作者
论文摘要
众所周知，平面带和分散狄拉克带在二维Kagome晶格中共存。包括相对论的自旋轨道耦合，此类系统通常表现出非平凡的带拓扑结构，从而可以在频带结构中多个位置和色散频段或Dirac频段交叉处的平坦带之间进行无间隙的边缘模式。在这里，我们从理论上证明了kagome晶格上的多功能系统是一个多功能平台，可探索非平凡的带拓扑与电子相互作用之间的相互作用。具体而言，在这里我们报告说，具有原子自旋轨道耦合的多灯塔kagome模型自然支持以非零Chern数字$ \ cal c $为特征的拓扑带，其中包括带有$ | {\ cal c} |的平坦频段。 = 1 $。当这样的平面带$ 1/3 $填充时，非本地排斥相互作用会引起分数Chern绝缘状态。我们还讨论了实际kagome材料中发现的可能实现。
Flat bands and dispersive Dirac bands are known to coexist in the electronic bands in a two-dimensional kagome lattice. Including the relativistic spin-orbit coupling, such systems often exhibit nontrivial band topology, allowing for gapless edge modes between flat bands at several locations in the band structure, and dispersive bands or at the Dirac band crossing. Here, we theoretically demonstrate that a multiorbital system on a kagome lattice is a versatile platform to explore the interplay between nontrivial band topology and electronic interaction. Specifically, here we report that the multiorbital kagome model with the atomic spin-orbit coupling naturally supports topological bands characterized by nonzero Chern numbers $\cal C$, including a flat band with $|{\cal C}| =1$. When such a flat band is $1/3$ filled, the non-local repulsive interactions induce a fractional Chern insulating state. We also discuss the possible realization of our findings in real kagome materials.
