Kagome晶格中的拓扑平带和量子霍尔效应

Topological Flat Band and Quantum Hall Effect in the Kagome Lattice

本文采用紧束缚模型研究Kagome晶格中的拓扑平带.通过调控交错磁通和次近邻跃迁强度可以得到具有大带隙且Chern数为非零的近平带结构.由于拓扑平带与二维Landau能级的相似性,所以此拓扑非平庸的平带可以产生整数量子霍尔态,再加上相互作用还可能产生分数量子霍尔态.

We study the topological flat band via tight-binding model in the Kagome lattice. A suitable combination of staggered flux and next nearest neighbor hopping can result in nearly flatband with a large band gap and nonzero Chern number. Because of the similarity with two-dimensional Landau levels, this topologically nontrivial nearly flatband can give rise to integer quantum Hall states and also may lead to fractional quantum Hall states by adding interactions.