LaTe3 is a noncentrosymmetric (NC) material with time reversal (TR) symmetry in which the charge density wave (CDW) is hosted by the Te bilayers. Here, we show that LaTe3 hosts a Kramers nodal line (KNL), a twofold degenerate nodal line that connects the TR invariant momenta in NC achiral systems, using angle resolved photoemission spectroscopy (ARPES), density functional theory (DFT), effective band structure (EBS) calculated by band unfolding, and symmetry arguments. DFT incorporating spin-orbit coupling (SOC) reveals that the KNL -- protected by the TR and lattice symmetries -- imposes gapless crossings between the bilayer-split CDW-induced shadow bands and the main bands. In excellent agreement with the EBS, ARPES data corroborate the presence of the KNL and show that the crossings traverse the Fermi level. Furthermore, spinless nodal lines - entirely gapped out by the SOC - are formed by the linear crossings of the shadow and main bands with a high Fermi velocity.
@article{arxiv.2212.01181,
title = {Charge density wave induced nodal lines in LaTe$_3$},
author = {Shuvam Sarkar and Joydipto Bhattacharya and Pampa Sadhukhan and Davide Curcio and Rajeev Dutt and Vipin Kumar Singh and Marco Bianchi and Arnab Pariari and Shubhankar Roy and Prabhat Mandal and Tanmoy Das and Philip Hofmann and Aparna Chakrabarti and Sudipta Roy Barman},
journal= {arXiv preprint arXiv:2212.01181},
year = {2023}
}