Three-dimensional band structure of LaSb and CeSb: Absence of band inversion
Three-dimensional band structure of LaSb and CeSb: Absence of band inversion
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DOI：
10.1103/physrevb.96.041120
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发表时间：
2017-07-18
影响因子：
3.7
通讯作者：
Sato, T.
中科院分区：
文献类型：
--
作者：
Oinuma, H.;Souma, S.;Sato, T.
我们对拓扑绝缘体候选材料 LaSb 和 CeSb 进行了角分辨光电子能谱 (ARPES)。使用软x射线光子，我们准确地确定了三维体能带结构，并揭示了LaSb和CeSb中不存在布里渊区角处的能带反转，这是实现拓扑绝缘体相的先决条件。此外，与使用软 X 射线光子获得的 ARPES 数据不同，使用 VUV 光子获得的 ARPES 数据被发现会遭受显着的 kz 展宽。这些结果表明，LaSb 和 CeSb 是拓扑平凡的半金属，并且用真空紫外光子观察到的不寻常的类狄拉克锥态并非拓扑起源。
We have performed angle-resolved photoemission spectroscopy (ARPES) of LaSb and CeSb, a candidate of topological insulators. Using soft-x-ray photons, we have accurately determined the three-dimensional bulk band structure and revealed that the band inversion at the Brillouin-zone corner, a prerequisite for realizing the topological-insulator phase, is absent in both LaSb and CeSb. Moreover, unlike the ARPES data obtained with soft-x-ray photons, those with VUV photons were found to suffer significant kz broadening. These results suggest that LaSb and CeSb are topologically trivial semimetals, and unusual Dirac-cone-like states observed with VUV photons are not of the topological origin.