Cyclotron excitations in pure bilayer graphene: Electron-hole asymmetry and Coulomb interaction

Inter-Landau-level transitions in the bilayer graphene in high perpendicular magnetic field at the filling-factor ν=0 have been studied. The next-nearest-neighbor transitions, energy difference between dimer and non-dimer sites, and layer asymmetry are included. The influence of Coulomb interaction is taken into account. The magnetoplasmon excitations in bilayer graphene at small momenta are considered within the Hartree-Fock approximation. The asymmetry in cyclotron resonance of clean bilayer graphene is shown to depend on magnetic field. At lower magnetic fields the energy splitting in the spectrum is due to electron-hole one-particle asymmetry while at higher magnetic fields it is due to Coulomb interaction. For the fully symmetric case with half-filled zero-energy levels the energy splitting proportional to the energy of Coulomb interaction is found.