Type-II Dirac semimetal candidates ATe2 ( A= Pt, Pd): A de Haas-van Alphen study

Abstract

We report on a magnetotransport and quantum oscillations study on high quality single crystals of the transition metal di-tellurides ${\mathrm{PtTe}}_{2}$ and ${\mathrm{PdTe}}_{2}$. The de Haas-van Alphen (dHvA) oscillations in the magnetization measurements on ${\mathrm{PtTe}}_{2}$ reveal a complicated, anisotropic band structure characterized by low effective masses and high mobilities for the carriers. Extracted transport parameters for ${\mathrm{PtTe}}_{2}$ reveal a strong anisotropy which might be related to the tilted nature of the Dirac cone. Using a Landau level fan diagram analysis we find at least one Fermi surface orbit with a Berry phase of $\ensuremath{\pi}$ consistent with Dirac electrons for both ${\mathrm{PtTe}}_{2}$ and ${\mathrm{PdTe}}_{2}$. The light effective mass and high mobility are also consistent with Dirac electrons in ${\mathrm{PtTe}}_{2}$. Our results therefore suggest that similar to ${\mathrm{PdTe}}_{2}$, ${\mathrm{PtTe}}_{2}$ might also be a three-dimensional Dirac semimetal.