Experimental observation of node-line-like surface states in LaBi
Experimental observation of node-line-like surface states in LaBi
复制标题
LaBi中节点线状表面态的实验观察
DOI：
10.1103/physrevb.97.155153
复制
发表时间：
2018-04-25
影响因子：
3.7
通讯作者：
Yao, Yugui
中科院分区：
文献类型：
--
作者：
Feng, Baojie;Cao, Jin;Yao, Yugui
在狄拉克节线半金属中，体导带和价带在布里渊区的延伸线处接触。迄今为止，大多数理论预测和实验发现的节线来自二维和三维材料的体带。在这里，结合角分辨光电子能谱测量和第一性原理计算的基础上，我们报告的发现节点线状表面状态的（001）表面的LaBi。这些能带来自LaBi的拓扑表面态，并桥接由自旋轨道耦合和能带反转打开的带隙。我们的第一性原理计算表明，这些“节线”有一个微小的差距，这是超出了典型的实验分辨率。这些结果可能为理解LaBi的特殊物理性质，如极大的磁电阻和电阻率平台提供重要信息。
In a Dirac nodal line semimetal, the bulk conduction and valence bands touch at extended lines in the Brillouin zone. To date, most of the theoretically predicated and experimentally discovered nodal lines derive from the bulk bands of two- and three-dimensional materials. Here, based on combined angle-resolved photoemission spectroscopy measurements and first-principles calculations, we report the discovery of node-line-like surface states on the (001) surface of LaBi. These bands derive from the topological surface states of LaBi and bridge the band gap opened by spin-orbit coupling and band inversion. Our first-principles calculations reveal that these "nodal lines" have a tiny gap, which is beyond typical experimental resolution. These results may provide important information to understand the extraordinary physical properties of LaBi, such as the extremely large magnetoresistance and resistivity plateau.