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-kz-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.
@article{arxiv.1708.06484,
title = {Topological surface electronic states in candidate nodal-line semimetal CaAgAs},
author = {Xiao-Bo Wang and Xiao-Ming Ma and Eve Emmanouilidou and Bing Shen and Chia-Hsiu Hsu and Chun-Sheng Zhou and Yi Zuo and Rong-Rong Song and Su-Yang Xu and Gan Wang and Li Huang and Ni Ni and Chang Liu},
journal= {arXiv preprint arXiv:1708.06484},
year = {2017}
}