Observation of Coexisting Dirac Bands and Moiré Flat Bands in Magic-Angle Twisted Trilayer Graphene

Publication

Author: Yiwei Li, Shihao Zhang, Fanqiang Chen, Liyang Wei, Zonglin Zhang, Hanbo Xiao, Han Gao, Moyu Chen, Shijun Liang, Ding Pei, Lixuan Xu, Kenji Watanabe, Takashi Taniguchi, Lexian Yang, Feng Miao, Jianpeng Liu, Bin Cheng, Meixiao Wang, Yulin Chen, Zhongkai Liu Advanced Materials
URL: https://doi.org/10.1002/adma.202205996
Date: 2022
Instruments: DA30-L

Moiré superlattices that consist of two or more layers of 2D materials stacked together with a small twist angle have emerged as a tunable platform to realize various correlated and topological phases, such as Mott insulators, unconventional superconductivity, and quantum anomalous Hall effect. Recently, magic-angle twisted trilayer graphene (MATTG) has shown both robust superconductivity similar to magic-angle twisted bilayer graphene and other unique properties, including the Pauli-limit violating and re-entrant superconductivity. These rich properties are deeply rooted in its electronic structure under the influence of distinct moiré potential and mirror symmetry. Here, combining nanometer-scale spatially resolved angle-resolved photoemission spectroscopy and scanning tunneling microscopy/spectroscopy, the as-yet unexplored band structure of MATTG near charge neutrality is systematically measured. These measurements reveal the coexistence of the distinct dispersive Dirac band with the emergent moiré flat band, showing nice agreement with the theoretical calculations. These results serve as a stepstone for further understanding of the unconventional superconductivity in MATTG.