Par complex cluster formation mediated by phase separation
Par complex cluster formation mediated by phase separation
复制标题
受挫戈薇晶格金属 CoSn 中的轨道选择性狄拉克费米子和极平坦能带
DOI：
10.1038/s41467-020-17462-4
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发表时间：
2020-05-08
影响因子：
16.6
通讯作者：
Wen, Wenyu
中科院分区：
文献类型：
--
作者：
Liu, Ziheng;Yang, Ying;Wen, Wenyu
层状kagome晶格3d过渡金属是一个令人兴奋的平台，探索挫折晶格几何和量子拓扑结构。然而，典型的kagome电子带，其特征是由相破坏的平带覆盖的狄拉克带，还没有被清楚地观察到，它们的轨道物理研究得更少。在这里，我们提出了接近教科书的CoSn中具有轨道微分物理的kagome带，它可以通过Co kagome晶格中具有单轨道跳跃的最小紧束缚模型很好地描述。带宽小于0.2 eV的平顶带贯穿整个布里渊区，尤其是面外轨道平坦带的带宽沿着Γ-M方向小于0.02 eV。在面外轨道的狄拉克锥处，自旋轨道相互作用引起的能隙比面内轨道小得多，表明狄拉克费米子具有轨道选择性。
Layered kagome-lattice 3dtransition metals are emerging as an exciting platform to explore the frustrated lattice geometry and quantum topology. However, the typical kagome electronic bands, characterized by sets of the Dirac-like band capped by a phase-destructive flat band, have not been clearly observed, and their orbital physics are even less well investigated. Here, we present close-to-textbook kagome bands with orbital differentiation physics in CoSn, which can be well described by a minimal tight-binding model with single-orbital hopping in Co kagome lattice. The capping flat bands with bandwidth less than 0.2 eV run through the whole Brillouin zone, especially the bandwidth of the flat band of out-of-plane orbitals is less than 0.02 eV along Γ−M. The energy gap induced by spin-orbit interaction at the Dirac cone of out-of-plane orbitals is much smaller than that of in-plane orbitals, suggesting orbital-selective character of the Dirac fermions.