Large bulk resistivity and surface quantum oscillations in the topological insulator Bi2Te2Se

TL;DR

This study demonstrates that Bi2Te2Se exhibits high bulk resistivity and clear surface quantum oscillations, making it an ideal material for exploring surface transport phenomena in topological insulators.

Contribution

The paper reports the discovery of Bi2Te2Se's high resistivity and surface quantum oscillations, clarifying bulk and surface transport channels for the first time.

Findings

High resistivity exceeding 1 Ohm-cm

Observation of Shubnikov-de Haas oscillations from surface Dirac fermions

Establishment of Bi2Te2Se as the best material for surface quantum transport studies

Abstract

Topological insulators are predicted to present novel surface transport phenomena, but their experimental studies have been hindered by a metallic bulk conduction that overwhelms the surface transport. We show that a new topological insulator, Bi2Te2Se, presents a high resistivity exceeding 1 Ohm-cm and a variable-range hopping behavior, and yet presents Shubnikov-de Haas oscillations coming from the surface Dirac fermions. Furthermore, we have been able to clarify both the bulk and surface transport channels, establishing a comprehensive understanding of the transport in this material. Our results demonstrate that Bi2Te2Se is the best material to date for studying the surface quantum transport in a topological insulator.