标题： 关于呼吸kagome晶格的能带拓扑性 显示英文标题

标题： On the band topology of the breathing kagome lattice

摘要： 二维二阶拓扑绝缘体在其角上表现出拓扑保护的零能态。 在文献中，具有最近邻跃迁的呼吸凯格姆晶格常被提及为二维二阶拓扑绝缘体的一个例子。 在这里，我们通过显式构造表明，呼吸凯格姆晶格的角态可以通过连续改变跃迁参数来消除，而无需破坏模型的任何对称性，无需关闭体和边界间隙，并且无需引入原模型中不存在的跃迁项。 此外，我们对具有与呼吸凯格姆晶格相同晶体对称性的所有三带格点模型进行拓扑分类，并表明尽管没有相具有受保护的零能角态，但一些相是受阻的原子极限，表现出填充异常。 显示英文摘要

摘要： A two-dimensional second-order topological insulator exhibits topologically protected zero-energy states at its corners. In the literature, the breathing kagome lattice with nearest-neighbor hopping is often mentioned as an example of a two-dimensional second-order topological insulator. Here we show by explicit construction that the corner states of the breathing kagome lattice can be removed by a continuous change of the hopping parameters, without breaking any of the model's symmetries, without closing bulk and boundary gaps, and without introducing hopping terms not present in the original model. Furthermore, we topologically classify all three-band lattice models with the same crystalline symmetries as the breathing kagome lattice and show that though none of the phases have protected zero-energy corner states, some of the phases are obstructed atomic limits which exhibit a filling anomaly.