转角In2Se3/Graphene异质结的界面调控及电子性质研究

转角In2Se3/Graphene异质结是最近发现的、继Graphene/hBN和转角石墨烯后、第三种具有超晶格诱导的莫尔（Moiré）狄拉克费米子重整化作用的体系，其中可能存在范霍夫奇点、关联绝缘态、非常规超导态等新奇的量子物态。该体系的优势在于，Moiré狄拉克锥出现在布里渊区中心Γ点附近，可以用角分辨光电子能谱直接精确探测其能带结构，这为探测和调控石墨烯异质结中新奇量子物态提供了新的研究平台。本项目拟采用分子束外延方式可控制备转角In2Se3/Graphene异质结，结合角分辨光电子能谱、扫描隧道显微镜/谱、输运测试和理论计算，系统研究转角对其界面电子性质的调控作用，探索特定转角下可能出现的强关联量子物态。通过本项目研究的开展，将有望阐明Moiré狄拉克费米子重整化作用的物理机制，并为其未来在光电子、自旋电子器件等方面的应用奠定基础。

The twisted In2Se3/graphene heterostructure is recently discovered as the third graphene-based system after graphene/hBN heterostructure and twisted bilayer graphene (TBG), in which the moiré Dirac fermions are renormalized by the superlattice potential. Peculiar physical phenomena might be emegent in this system, such as van Hove singularity, correlated insulating state, unconventional superconducting state, etc. In twisted In2Se3/graphene heterostructure, the moiré Dirac cones exist around Γ point at the graphene Brillouin zone center (rather than around K point at the Brillouin zone corners in graphene/hBN and TBG). This advantage makes it possible to detect the bandstructure directly and accurately via angle-resolved photoemission spectroscopy, thus providing a new research platform for detecting and manipulating these novel quantum states in graphene-related heterostructures. In this research project, based on controllable preparation of twisted In2Se3/graphene heterostructure via molecular beam epitaxy, the interface electronic properties engineered by the twisted angle will be systematically studied by combining angle-resolved photoemission spectroscopy, scanning tunneling microscopy/spectroscopy, transport measurement, as well as theoretical calculations. The correlated states which might be emergent at a specific twisted angle would be further explored. Our project will benefit to deepen the comprehension of novel quantum phenomena related to moiré superlattice, further reveal the mechanism of moiré Dirac fermion renormalization, as well as pave a way for future heterostructure-based device applications in optoelectronics and spintronics.