Bulk Fermi surfaces of the Dirac type-II semimetallic candidate NiTe₂

Here, we present a study on the Fermi-surface of the Dirac type-II semi-metallic candidate NiTe₂ via the temperature and angular dependence of the de Haas-van Alphen (dHvA) effect measured in single-crystals grown through Te flux. In contrast to its isostructural compounds like PtSe₂, band structure calculations predict NiTe₂ to display a tilted Dirac node very close to its Fermi level that is located along the Γ to A high symmetry direction within its first Brillouin zone (FBZ). The angular dependence of the dHvA frequencies is found to be in agreement with the first-principle calculations when the electronic bands are slightly shifted with respect to the Fermi level (ε_F), and therefore provide support for the existence of a Dirac type-II node in NiTe₂. Despite the coexistence of Dirac-like fermions with topologically trivial carriers, samples of the highest quality display an anomalous and large, either linear or sub-linear magnetoresistivity. This suggests that Lorentz invariance breaking Dirac-like quasiparticles dominate the carrier transport in this compound.