论文标题
三角kagome晶格及其庞大的对应关系上的脆弱拓扑阶段
Fragile topological phase on the triangular kagome lattice and its bulk-boundary correspondence
论文作者
论文摘要
我们使用紧密结合（TB）模型（TB）模型和拓扑量子化学理论（TQC）预测和检查各种拓扑状态。首先，在TQC的基础上，我们诊断具有脆弱拓扑结构的带结构，并计算Wilson-Loop Spectra和Hofstadter Butterfly Spectra，以确认它们的非平凡性质。其次，我们检查了庞大的边界对应关系，发现阻塞的原子限制（OAL）绝缘子宿主宿主是分数角状态而不会伴随着脆弱的拓扑带结构，这意味着OAL和角状态的存在不是足够的条件来脆弱。最后但并非最不重要的一点是，我们预测了从二阶拓扑阶段到一阶拓扑阶段的拓扑相变，该阶段可以在磁场的作用下在TKL中实现。
We predict and examine various topological states on a two-dimensional (2D) triangular kagome lattice (TKL) using the tight-binding (TB) models and theory of topological quantum chemistry (TQC). Firstly, on the basis of TQC, we diagnose band structures with fragile topology and calculate Wilson-loop spectra and Hofstadter butterfly spectra to confirm their non-trivial nature. Secondly, we examine the bulk-boundary correspondence and find that an obstructed-atomic-limit (OAL) insulator hosts fractional corner states without being accompanied by fragile topological band structures, which implies that the presence of OALs and corner states is not a sufficient condition to fragile topology. Last but not least, we predict a topological phase transition from a second-order topological phase to a first-order topological phase that can be realized in the TKL under the action of a magnetic field.
