Bulk Dirac cone and highly anisotropic electronic structure of Ni Te 2

Transition-metal dichalcogenides (TMDCs) hosting type-II Dirac fermions have attracted a great deal of research interest owing to their rich application capabilities. Here, we have systematically investigated the bulk and surface electronic structures of type-II Dirac semimetal NiTe2 by means of angle-resolved photoelectron spectroscopy (ARPES) combined with first-principles calculations. As a result, a bulk Dirac point located 150 meV below the Fermi energy is directly observed by using bulk-sensitive soft x-ray ARPES. Moreover, the measured Fermi surfaces of NiTe2 are found to be strongly anisotropic. The first-principles calculations, which match remarkably well with the experimental results, show that the energy position of the Dirac point crucially depends on a small variation of the structural parameters. Our work establishes NiTe2 as an ideal platform for further investigating the anisotropic magnetotransport associated with type-II Dirac fermions in TMDCs and paves the way for prospective applications.