Inter-valley spiral order in the Mott insulating state of a heterostructure of trilayer graphene-boron nitride

• 来源期刊: 科学通报（英文版）
• 年，卷（期）: 2018,（17）
• 页码范围: 1087-1091
• 页数: 5页
• 语种: 英文

摘要

Recent experiment has shown that the ABC-stacked trilayer graphene-boron nitride Moire super-lattice at half-filling is a Mott insulator.Based on symmetry analysis and effective band structure calculation,we propose a valley-contrasting chiral tight-binding model with local Coulomb interaction to describe this Moire super-lattice system.By matching the positions of van Hove points in the low-energy effective bands,the valley-contrasting staggered flux per triangle is determined around π/2.When the valence band is half-filled,the Fermi surfaces are found to be perfectly nested between the two valleys.Such an effect can induce an inter-valley spiral order with a gap in the charge excitations,indicating that the Mott insulating behavior observed in the trilayer graphene-boron nitride Moire super-lattice results predominantly from the inter-valley scattering.