Hot 2DHG states in tellurium

TL;DR

This paper reports the discovery of robust, high-temperature two-dimensional hole gas surface states in tellurium, exhibiting Shubnikov-de Haas oscillations up to 200 K, indicating potential for high-temperature quantum transport applications.

Contribution

It reveals the existence of hot 2DHG states in tellurium with topological characteristics, demonstrating their robustness across different samples and doping conditions.

Findings

SdH oscillations observed up to 200 K in Te crystals

Nontrivial Berry phase indicating topological states

Robustness of oscillations across defected and doped samples

Abstract

Element semiconductor Te is very popular in both fundamental electronic structure study, and device fabrication research area due to its unique band structure. Specifically, in low temperatures, Te possesses strong quantum oscillations with magnetic field applied in basal plane, either following Shubnikov-de Haas (SdH) oscillation rule or following log-periodic oscillation rule. With magnetic field applied along the [001] direction, the SdH oscillations are attributed to the two-dimensional hole gas (2DHG) surface states. Here we reported an interesting SdH oscillation in Te-based single crystals, with the magnetic field applied along the [001] direction of the crystals, showing the maximum oscillation intensity at ~ 75 K, and still traceable at 200 K, which indicates a rather hot 2DHG state. The nontrivial Berry phase can be also obtained from the oscillations, implying the contribution from topological states. More importantly, the high temperature SdH oscillation phenomena are observed in different Te single crystals samples, and Te single crystals with nonmagnetic/magnetic dopants, showing robustness to bulk defects. Therefore, the oscillation may be contributed by the bulk symmetry protected hot 2DHG states, which will offer a new platform for high-temperature quantum transport studies.