Evidence for topological proximity effect in graphene coupled to topological insulator

Abstract

The emergence of topological order in graphene is in great demand for the realization of quantum spin Hall states. Recently, it is theoretically proposed that the spin textures of surface states in topological insulator can be directly transferred to graphene by means of proximity effect. Here we report the observations of the topological proximity effect in the graphene-topological insulator Bi2Se3 heterojunctions via magnetotransport measurements. The coupling between the p_z orbitals of graphene and the p orbitals of surface states on the Bi2Se3 bottom surface can be enhanced by applying perpendicular negative magnetic field, resulting in a giant negative magnetoresistance at the Dirac point up to about -91%. An obvious resistivity dip in the transfer curve at the Dirac point is also observed in the hybrid devices, which is consistent with the theoretical predictions of the distorted Dirac bands with unique spin textures inherited from Bi2Se3 surface states.

References in corpus (7)

• Discovery (theoretical prediction and experimental observation) of a large-gap topological-insulator class with spin-polarized single-Dirac-cone on the surface
• Carrier transport in 2D graphene layers
• A self-consistent theory for graphene transport
• Spin-Orbit Proximity Effect in Graphene
• Quantum Anomalous Hall Effect in Graphene Proximity Coupled to an Antiferromagnetic Insulator
• Charge Transport and Inhomogeneity near the Charge Neutrality Point in Graphene
• Quantum spin Hall states in graphene interacting with WS${}_2$ or WSe${}_2$

Cited by in corpus (6)

• Spin Proximity Effects in Graphene/Topological Insulator Heterostructures
• Effective Interactions in a Graphene Layer Induced by the Proximity to a Ferromagnet
• Magic angle conditions for twisted 3D topological insulators
• Proximity-Induced Spin-Orbit Coupling in Graphene-Bi${}_{1.5}$Sb${}_{0.5}$Te${}_{1.7}$Se${}_{1.3}$ Heterostructures
• Landau quantization in buckled monolayer GaAs
• Universally optimizable strategy for magnetic gaps towards high-temperature quantum anomalous Hall states via magnetic-insulator/topological-insulator building-blocks