Resolving the Dirac Cone on the Surface of Bi2Te3 Topological Insulator Nanowires by Field-Effect Measurements

TL;DR

This paper demonstrates a method using field-effect and magnetoresistance measurements to confirm the Dirac cone and topological surface states in Bi2Te3 nanowires, providing a practical identification technique.

Contribution

It introduces a straightforward approach to resolve the Dirac cone and validate topological insulator surface states in nanowires without needing angle-resolved photoemission spectroscopy.

Findings

Confirmed the linear dispersion relation of surface states

Measured carrier concentration, mobility, and cyclotron mass in agreement with models

Provided a practical method for identifying topological insulators

Abstract

We validate the linear dispersion relation and resolve the Dirac cone on the surface of a single Bi2Te3 nanowire via a combination of field-effect and magnetoresistance measurements by which we unambiguously prove the topological insulator nature of the nanowire surface states. Moreover we show that the experimentally determined carrier concentration, mobility and cyclotron mass of the surface states are in excellent agreement with relativistic models. Our method provides a facile way to identify topological insulators that too small for angle-resolved photo emission spectroscopy.