Transition-metal dichalcogenides (TMDs) offer an ideal platform to experimentally realize Dirac fermions. However, typically these exotic quasiparticles are located far away from the Fermi level, limiting the contribution of Dirac-like carriers to the transport properties. Here we show that NiTe2 hosts both bulk Type-II Dirac points and topological surface states. The underlying mechanism is shared with other TMDs and based on the generic topological character of the Te p-orbital manifold. However, unique to NiTe2, a significant contribution of Ni d orbital states shifts the energy of the Type-II Dirac point close to the Fermi level. In addition, one of the topological surface states intersects the Fermi energy and exhibits a remarkably large spin splitting of 120 meV. Our results establish NiTe2 as an exciting candidate for next-generation spintronics devices.
@article{arxiv.1912.08535,
title = {Fermi-crossing Type-II Dirac fermions and topological surface states in NiTe2},
author = {Saumya Mukherjee and Sung Won Jung and Sophie F. Weber and Chunqiang Xu and Dong Qian and Xiaofeng Xu and Pabitra K. Biswas and Timur K. Kim and Laurent C. Chapon and Matthew D. Watson and Jeffrey B. Neaton and Cephise Cacho},
journal= {arXiv preprint arXiv:1912.08535},
year = {2020}
}