论文标题
Kagome Lattices in Kagome lattices pd $ _3 $ pb $ _2 $ x $ x $ _2 $（x = s，se）中的高阶fermi弧的可调式狄拉克半金属
Tunable Dirac Semimetals with Higher-order Fermi Arcs in Kagome Lattices Pd$_3$Pb$_2$X$_2$ (X = S, Se)
论文作者
论文摘要
在拓扑状态的识别中，散装的对应关系取得了巨大的成功。但是，这种优雅的策略不适用于Dirac半学（DSM）。在这里，我们建议Kagome Lattices PD $ _3 $ _2 $ _2 $ x $ _2 $（X = S，SE）是没有表面Fermi Arc状态的唯一类型I DSM，与以前众所周知的DSMS不同，例如Na $ _3 $ _3 $ bi和cd $ _3 $ as $ _2 $ $ _2 $。 pd $ _3 $ pb $ _2 $ x $ _2 $的特征是非平凡的拓扑不变Z $ _3 $，保证了高阶散装式通讯和高阶Fermi Arcs的存在，以及铰链上的分数角度指控。 I型DSM位于几个拓扑阶段的相边界，包括II型DSM和三维弱拓扑绝缘子。相变很容易通过外部应变来操纵。我们的结果为研究这些独特的DSM和相关相变的研究提供了可行的平台。
Bulk-boundary correspondence has achieved a great success in the identification of topological states. However, this elegant strategy doesn't apply to the Dirac semimetals (DSMs). Here, we propose that kagome lattices Pd$_3$Pb$_2$X$_2$ (X = S, Se) are unique type-I DSMs without surface Fermi arc states, which are different from the previous well-known DSMs, such as Na$_3$Bi and Cd$_3$As$_2$. Pd$_3$Pb$_2$X$_2$ are characterized by nontrivial topological invariant Z$_3$, guaranteeing a higher-order bulk-hinge correspondence and the existence of higher-order Fermi arcs, as well as fractional corner charges on the hinges. The type-I DSMs are located at the phase boundaries of several topological phases, including type-II DSMs and three-dimensional weak topological insulators. The phase transitions can be easily manipulated by external strain. Our results provide feasible platforms for the study of these unique DSMs and the related phase transitions.
