论文标题
石墨烯带的“阴影”可以阐明其平坦度吗？
Can the "shadow" of graphene band clarify its flatness?
论文作者
论文摘要
在van霍夫奇异性（VHS）接近处的石墨烯带重归其化，已经通过在钴表面上的Li掺杂的准准养殖石墨烯上的角度分辨光发射光谱（ARPE）研究了。与底物没有石墨烯条带杂交，以刚性能量移位为代表的掺杂贡献和金属底物确保了出色的电子电子相互作用筛选为这种研究提供了特权的观点。沿石墨烯布里渊区的M点检测到明显的ARPES信号，从而产生了明显的扁平带。通过模拟从密度功能理论计算的石墨烯光谱函数，我们证明了沿M点的光发射信号源自费米级上方无人频段的光谱函数的“阴影”。这种解释提出了在VHS接近度上没有任何其他强相关效应，即使在高度掺杂的情况下，也可以调解石墨烯带结构的平均场描述。
Graphene band renormalization at the proximity of the van Hove singularity (VHS) has been investigated by angle-resolved photoemission spectroscopy (ARPES) on the Li-doped quasi-freestanding graphene on the cobalt (0001) surface. The absence of graphene band hybridization with the substrate, the doping contribution well represented by a rigid energy shift and the excellent electron-electron interaction screening ensured by the metallic substrate offer a privileged point of view for such investigation. A clear ARPES signal is detected along the M point of the graphene Brillouin zone, giving rise to an apparent flattened band. By simulating the graphene spectral function from the density functional theory calculated bands, we demonstrate that the photoemission signal along the M point originates from the "shadow" of the spectral function of the unoccupied band above the Fermi level. Such interpretation put forward the absence of any additional strong correlation effects at the VHS proximity, reconciling the mean field description of the graphene band structure even in the highly doped scenario.
