  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.
