Realization of Topological Mott Insulator in a Twisted Bilayer Graphene Lattice Model (Jun. 23, 2021)

  • Published: 2021-06-22

Time: 10:00am (UTC/GMT+8:00, Beijing/Shanghai), Jun. 23, 2021

Venue: KITS Meeting Room, No. 7 Building, UCAS [View Map]


Speaker: Binbin Chen (BUAA)



Magic-angle twisted bilayer graphene (TBG) has recently become a new material platform realizing correlated electron phenomena taking place within its topological flat bands. Several numerical and analytical methods have been applied to understand the correlated phases of TBG, revealing some similarity with the quantum Hall physics.


In this talk, I'll present our recent work on a TBG-related lattice model which provide a Mott-Hubbard perspective for the TBG system. By employing the large-scale density matrix renormalization group (DMRG) on the lattice model containing the projected Coulomb interactions only, we identify a quantum anomalous Hall (QAH) state with Chern number of ±1, and an insulating stripe state, separated by a first-order quantum phase transition.


Our results shed light on the mechanism of QAH discovered at three-quarters filling, and provide a first instance of the topological Mott insulator, i.e., the QAH state in the strong coupling limit.


About the Speaker:

陈斌斌 (北京航空航天大学物理学院


20159 – 2021 6  北京航空航天大学 物理学院 博士学习

2018 2 – 2020 2   德国慕尼黑大学 Jan von Delft研究组 联合培养

2021 5 至今  国科大卡夫里理论科学研究所 苏刚教授研究组 访问交流



Invited by Prof. Long Zhang