Galvanomagnetic properties of the putative type-II Dirac semimetal PtTe$_2$

TL;DR

This study investigates the magnetotransport properties of PtTe₂, a candidate type-II Dirac semimetal, revealing large magnetoresistance, quantum oscillations, and a multi-band electronic structure with trivial Berry phases.

Contribution

The paper provides detailed magnetotransport measurements of PtTe₂, demonstrating its complex electronic behavior and clarifying its topological nature through experimental data.

Findings

Large unsaturated magnetoresistance over 3000% at 1.8 K

Observation of Shubnikov-de Haas oscillations with small effective masses

Hall effect indicates multi-band conduction with trivial Berry phases

Abstract

Platinum ditelluride has recently been characterized, based on angle-resolved photoemission spectroscopy data and electronic band structure calculations, as a possible representative of type-II Dirac semimetals. Here, we report on the magnetotransport behavior (electrical resistivity, Hall effect) in this compound, investigated on high-quality single-crystalline specimens. The magnetoresistance (MR) of PtTe$_2$ is large (over $3000\%$ at $T=1.8$ K in $B=9$ T) and unsaturated in strong fields in the entire temperature range studied. The MR isotherms obey a Kohler's type scaling with the exponent $m$ = 1.69, different from the case of ideal electron-hole compensation. In applied magnetic fields, the resistivity shows a low-temperature plateau, characteristic of topological semimetals. In strong fields, well-resolved Shubnikov - de Haas (SdH) oscillations with two principle frequencies were found, and their analysis yielded charge mobilities of the order of $10^3\,\rm{cm^2V^{-1}s^{-1}}$ and rather small effective masses of charge carriers, $0.11m_e$ and $0.21m_e$. However, the extracted Berry phases point to trivial character of the electronic bands involved in the SdH oscillations. The Hall effect data corroborated a multi-band character of the electrical conductivity in PtTe$_2$, with moderate charge compensation.