Probing the Plasmon-Phonon Hybridization in Supported Graphene by Externally Moving Charged Particles

We use the dielectric response formalism to show how an incident charged particle may be used to probe the hybridization taking place between the Dirac plasmon in graphene and the surface optical phonon modes in a SiO2 substrate. Strong effects of this hybridization are found in the wake pattern in the induced potential, as well as in the stopping and image forces that act on the incident charge in a broad range of its velocities. Particularly intriguing is the possibility to control the plasmon-phonon hybridization by varying the doping density of graphene, where the regime of a nominally neutral graphene is expected to give rise to dramatic effects in the energy loss of charged particles that move at the velocities below the Fermi velocity of graphene