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arXiv · 1707.05100

Three-dimensional band structure of LaSb and CeSb:Absence of band inversion

H. Oinuma·S. Souma·D. Takane·T. Nakamura·K. Nakayama·T. Mitsuhashi·K. Horiba·H. Kumigashira·M. Yoshida·A. Ochiai·T. Takahashi·T. Sato
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Abstract

We have performed angle-resolved photoemission spectroscopy (ARPES) of LaSb and CeSb, a candidate of topological insulator. 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 topological-insulator phase - is absent in both LaSb and CeSb. Moreover, unlike the ARPES data obtained with soft-x-ray photons, those with vacuum ultraviolet (VUV) photons were found to suffer significant $k_z$ 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.

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H. Oinuma, S. Souma, D. Takane, T. Nakamura, K. Nakayama, T. Mitsuhashi, K. Horiba, H. Kumigashira, M. Yoshida, A. Ochiai, T. Takahashi, T. Sato. 2017-07-17. Three-dimensional band structure of LaSb and CeSb:Absence of band inversion. https://doi.org/10.1103/physrevb.96.041120

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