Li Yiwei, Zhang Shihao, Chen Fanqiang, Wei Liyang, Zhang Zonglin, Xiao Hanbo, Gao Han, Chen Moyu, Liang Shijun, Pei Ding, Xu Lixuan, Watanabe Kenji, Taniguchi Takashi, Yang Lexian, Miao Feng, Liu Jianpeng, Cheng Bin, Wang Meixiao, Chen Yulin, Liu Zhongkai
School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, P. R. China.
Institute for Advanced Studies, Wuhan University, Luojiashan Street, Wuhan, Hubei, 430072, P. R. China.
Adv Mater. 2022 Oct;34(42):e2205996. doi: 10.1002/adma.202205996. Epub 2022 Sep 16.
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.
由两层或更多层二维材料以小扭转角堆叠在一起组成的莫尔超晶格，已成为实现各种关联和拓扑相的可调谐平台，如莫特绝缘体、非常规超导和量子反常霍尔效应。最近，魔角扭曲三层石墨烯（MATTG）既表现出与魔角扭曲双层石墨烯相似的稳健超导性，又具有其他独特性质，包括违反泡利极限和再入超导性。这些丰富的性质深深植根于其在独特莫尔势和镜面对称性影响下的电子结构。在此，结合纳米尺度空间分辨角分辨光电子能谱和扫描隧道显微镜/能谱，系统测量了MATTG在电荷中性附近尚未探索的能带结构。这些测量揭示了独特的色散狄拉克带与出现的莫尔平带共存，与理论计算结果吻合良好。这些结果为进一步理解MATTG中的非常规超导性奠定了基础。
