Multi-frequency Shubnikov-de Haas oscillations in topological semimetal Pt$_2$HgSe$_3$

TL;DR

This study reports the observation of multi-frequency Shubnikov-de Haas oscillations in bulk jacutingaite, a topological semimetal, and demonstrates its potential as a platform for 2D quantum spin Hall transport investigations.

Contribution

It provides the first transport measurements on jacutingaite, revealing its semimetallic nature and detailed quantum oscillation analysis aligned with band structure calculations.

Findings

Jacutingaite exhibits multi-frequency SdH oscillations.

The material has high electron mobility (~2000 cm²/Vs).

Experimental results agree with ab-initio band structure calculations.

Abstract

Monolayer jacutingaite (Pt$_2$HgSe$_3$) has been recently identified as a candidate quantum spin Hall system with a 0.5 eV band gap, but no transport measurements have been performed so far on this material, neither in monolayer nor in the bulk. By using a dedicated high-pressure technique, we grow crystals enabling the exfoliation of 50-100 nm thick layers and the realization of devices for controlled transport experiments. Magnetoresistance measurements indicate that jacutingaite is a semimetal, exhibiting Shubnikov-de Haas (SdH) resistance oscillations with a multi-frequency spectrum. We adapt the Lifshitz-Kosevich formula to analyze quantitatively the SdH resistance oscillations in the presence of multiple frequencies, and find that the experimental observations are overall reproduced well by band structure ab-initio calculations for bulk jacutingaite. Together with the relatively high electron mobility extracted from the experiments ($\approx 2000$ cm$^2$/Vs, comparable to what is observed in WTe$_2$ crystals of the same thickness), our results indicate that monolayer jacutingaite should provide an excellent platform to investigate transport in 2D quantum spin Hall systems.