Unusual electronic excitations in ABA trilayer graphene

The tight-binding model is closely associated with the modified random-phase approximation to thoroughly explore the electron–electron interactions in trilayer AB-stacked graphene. The intralayer and interlayer atomic/Coulomb interactions dominate the collective and electron–hole excitations. The unusual energy bands are directly reflected in the diverse transferred momentum–frequency phase diagrams. There exist three kinds of plasmon modes during the variation of the doping level, being accompanied with the complicated intraband and interband single-particle excitations. The excitation behaviors are greatly diversified by the number of layers. The theoretical predictions require the high-resolution experimental examinations.