Tunable Dirac semimetals with higher-order Fermi arcs in Kagome lattices Pd3Pb2X2 (X=S,Se).
Tunable Dirac semimetals with higher-order Fermi arcs in Kagome lattices Pd3Pb2X2 (X=S,Se).
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DOI：
10.1016/j.scib.2022.09.003
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发表时间：
2022-03
期刊：
影响因子：
18.9
通讯作者：
S. Nie;Jia Chen;C. Yue;C. Le;Danwen Yuan;Wei Zhang;H. Weng
中科院分区：
文献类型：
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作者：
S. Nie;Jia Chen;C. Yue;C. Le;Danwen Yuan;Wei Zhang;H. Weng
体界对应在识别拓扑态方面取得了巨大的成功。然而，这一优雅的策略并不适用于狄拉克半金属(DSM)。在这里，我们提出了Kagome晶格PdPbX(X=S，Se)是唯一的没有表面费米弧态的I型DSM，它不同于以往著名的DSM，如NaBI和CDAs。PdPbX的特征是非平凡的拓扑不变量Z，它保证了高阶体铰链对应关系和高阶费米弧的存在，以及铰链上分数角电荷的存在。I型DSM位于几个拓扑相的相界上，包括II型DSM和三维弱拓扑绝缘子。相变可以很容易地通过外部应变来操纵。我们的结果为研究这些独特的深亚微米及其相关相变提供了可行的平台。
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 PdPbX(X = S, Se) are unique type-I DSMs without surface Fermi arc states, which are different from the previous well-known DSMs, such as NaBi and CdAs. PdPbXare characterized by nontrivial topological invariant Z, 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.