Large Rashba Spin-Orbit Coupling and High-Temperature Quantum Anomalous Hall Effect in Re-Intercalated Graphene/CrI${}_3$ Heterostructure

Abstract

In 2010, quantum anomalous Hall effect (QAHE) in graphene was proposed in the presence of Rashba spin-orbit coupling and ferromagnetic exchange field. After a decade's experimental exploration, the anomalous Hall conductance can only reach about 0.25 in the units of $2e^2/h$, which was attributed to the tiny Rashba spin-orbit coupling. Here, we theoretically show that Re-intercalation in graphene/CrI${}_3$ heterostructure can not only induce sizeable Rashba spin-orbit coupling ($>$ 40~meV), but also open up large band gaps at valleys $K$ (22.2 meV) and $K^{\prime }$ (30.3 meV), and a global band gap over 5.5 meV (19.5 meV with random Re distribution) hosting QAHE. A low-energy continuum model is constructed to explain the underlying physical mechanism. We find that Rashba spin-orbit coupling is robust against external stress whereas a tensile strain can increase the global bulk gap. Furthermore, we also show that Re-intercalated graphene with hexagonal boron-nitride can also realize QAHE with bulk gap over 40~meV, indicating the tunability of $5d$-intercalated graphene-based heterostructure. Our finding makes a great leap towards the experimental realization of graphene-based QAHE, and will definitely accelerate the practical application of graphene-based low-power electronics.

References in corpus (10)

• Quantized Anomalous Hall Effect in Magnetic Topological Insulators
• Magnetic 2D materials and heterostructures
• Quantum Anomalous Hall Effect in Graphene from Rashba and Exchange Effects
• Proximity-induced ferromagnetism in graphene revealed by anomalous Hall effect
• Quantum Anomalous Hall Effect in Graphene Proximity Coupled to an Antiferromagnetic Insulator
• Quantum Anomalous Hall Effects in Graphene from Proximity-Induced Uniform and Staggered Spin-Orbit and Exchange Coupling
• Europium Underneath Graphene on Ir(111): Intercalation Mechanism, Magnetism, and Band Structure
• Dirac Fermion in Strongly-Bound Graphene Systems
• Gate-tunable proximity effects in graphene on layered magnetic insulators
• Rashba interaction and local magnetic moments in a graphene-Boron Nitride heterostructure by intercalation with Au

Cited by in corpus (2)

• The Layer Hall Effect without External Electric Field
• Spin-dependent $\pi$${\pi }^{\ast }$ gap in graphene on a magnetic substrate