A de Hass-van Alphen study of the Type-II Dirac semimetal candidates $A$Te$_2$ ($A =$ Pt, Pd)

TL;DR

This study investigates the electronic properties of PtTe2 and PdTe2, revealing evidence of Dirac electrons and anisotropic band structures, suggesting that PtTe2 is also a three-dimensional Dirac semimetal.

Contribution

It provides the first detailed magneto-transport and quantum oscillation analysis of PtTe2, demonstrating its potential as a 3D Dirac semimetal similar to PdTe2.

Findings

Evidence of Dirac electrons with a Berry phase of π in both materials

Observation of anisotropic band structures with low effective masses

PtTe2 exhibits high mobility consistent with Dirac semimetals

Abstract

We report on a magneto-transport and quantum oscillations study on high quality single crystals of the transition metal di-tellurides PtTe$_2$ and PdTe$_2$. The de Haas-van Alphen (dHvA) oscillations in the magnetization measurements on PtTe$_2$ reveal a complicated, anisotropic band structure characterized by low effective masses and high mobilities for the carriers. Extracted transport parameters for PtTe$_2$ reveal a strong anisotropy which could be related to the tilted nature of Dirac cone. Using a Landau level fan diagram analysis we find at least one Fermi surface orbit with a Berry phase of $\pi$ consistent with Dirac electrons for both PtTe$_2$ and PdTe$_2$. The light effective mass and high mobility are also consistent with Dirac electrons in PtTe$_2$. Our results suggest that similar to PdTe$_2$, PtTe$_2$ might also be a three dimensional Dirac semimetal.