Topological surface electronic states in candidate nodal-line semimetal CaAgAs
Topological surface electronic states in candidate nodal-line semimetal CaAgAs
复制标题
候选节点线半金属 CaAgAs 的拓扑表面电子态
DOI：
10.1103/physrevb.96.161112
复制
发表时间：
2017
影响因子：
3.7
通讯作者：
Chang Liu
中科院分区：
文献类型：
--
作者：
Xiao-Bo Wang;Xiao-Ming Ma;Eve Emmanouilidou;Bing Shen;Chia-Hsiu Hsu;Chun-Sheng Zhou;Yi Zuo;Rong-Rong Song;Su-Yang Xu;Gan Wang;Li Huang;Ni Ni;Chang Liu
我们通过角分辨光电子能谱和密度泛函计算系统地研究了候选节点线半金属 CaAgAs 的体和表面电子结构。我们观察到一个金属的、线性的、非$k_z$色散的表面带，它与理论拓扑表面态的高结合能部分一致，证明了该系统的拓扑非平凡性。实验费米能级的整体下移表明样品出现了刚性带状 $p$ 掺杂，这可能是由于生长晶体中的银空位所致。
We investigate systematically the bulk and surface electronic structure of the candidate nodal-line semimetal CaAgAs by angle resolved photoemission spectroscopy and density functional calculations. We observed a metallic, linear, non-$k_z$-dispersive surface band that coincides with the high-binding-energy part of the theoretical topological surface state, proving the topological nontriviality of the system. An overall downshift of the experimental Fermi level points to a rigid-band-like $p$-doping of the samples, due possibly to Ag vacancies in the as-grown crystals.