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 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.
@article{arxiv.1707.05100,
title = {Three-dimensional band structure of LaSb and CeSb:Absence of band inversion},
author = {H. Oinuma and S. Souma and D. Takane and T. Nakamura and K. Nakayama and T. Mitsuhashi and K. Horiba and H. Kumigashira and M. Yoshida and A. Ochiai and T. Takahashi and T. Sato},
journal= {arXiv preprint arXiv:1707.05100},
year = {2017}
}
Comments
5 pages, 3 figures, to appear in Phys. Rev. B, Rapid Communications