| Popis: |
We study the coupling between plasmon modes due to the long-range Coulomb electron–electron interaction for a composite system consisting of a two- dimensional system of Dirac electrons placed in three-dimensional Dirac semimetal. The mixing of the collective plasmon modes is obtained as the two- dimensional acoustic plasmon mode dispersion crosses the bulk plasmon mode. We show that the coupled plasmon modes become more separated with decreasing spacing between the two subsystems as the coupling increases due to the enhanced Coulomb interaction between electrons from different subsystems. We also investigate the effects of the Dirac cone tilts and anisotropies on coupled plasmon modes in both subsystems and find that they increase the coupled plasmon mode energies and renormalize their spectral weights. The anisotropic effects of tilts are more significant for the larger separations of the subsystems when the Coulomb coupling is weaker. |
