ABSTRACT
The Coulomb excitation behaviors are mainly determined by the electronic structures and geometric symmetries. The trilayer ABA stacking exhibits the unusual energy bands, two pairs of parabolic valence and conduction bands and one pair of distorted Dirac-cone structures; the corresponding van Hove singularities are presented in the density of states. For trilayer ABA stacking, the tight-binding model and the modified random-phase approximation are directly combined to thoroughly explore the diverse electronic excitations under intrinsic and extrinsic cases. The trilayer AB stacking has three pairs of low-lying valence and conduction bands, with a small band overlap. The Coulomb excitations are greatly diversified by the stacking configuration and layer number. Monolayer graphene, with the linear Dirac-cone structure, only exhibits interband excitations in the absence of carrier doping. In general, the energy loss functions, the Landau dampings, and the plasmon modes in trilayer ABA stacking do not exhibit the excitation phenomena suitable for the superposition of the monolayer-and bilayer-like ones, as obviously illustrated.
