Experimental Observation of Two Massless Dirac-Fermion Gases in Graphene-Topological Insulator Heterostructure

TL;DR

This paper reports the successful fabrication and characterization of a graphene-topological insulator heterostructure, revealing coexistence of two types of massless Dirac fermions and potential for tunable electronic properties.

Contribution

It introduces a practical method to create graphene-TI heterostructures and confirms the coexistence of Dirac states via ARPES measurements, advancing the study of interacting Dirac fermions.

Findings

Coexistence of topological surface states and graphene Dirac bands confirmed by ARPES.

Identification of twist angle in the heterostructure.

Potential for tunable electronic transport properties.

Abstract

Graphene and topological insulators (TI) possess two-dimensional Dirac fermions with distinct physical properties. Integrating these two Dirac materials in a single device creates interesting opportunities for exploring new physics of interacting massless Dirac fermions. Here we report on a practical route to experimental fabrication of graphene-Sb2Te3 heterostructure. The graphene-TI heterostructures are prepared by using a dry transfer of chemical-vapor-deposition grown graphene film. ARPES measurements confirm the coexistence of topological surface states of Sb2Te3 and Dirac {\pi} bands of graphene, and identify the twist angle in the graphene-TI heterostructure. The results suggest a potential tunable electronic platform in which two different Dirac low-energy states dominate the transport behavior.