  The present work deals with a theoretical research on the emission and
radiation properties of a dipole emitter source close to a dimer graphene
plasmonic antenna. Modification of the radiation and the quantum efficiencies
resulting from varying the position of the emitter and the orientation of its
dipole moment are calculated by using a rigorous electromagnetic method based
on Green's second identity. Large enhancements in the emission and the
radiation of the emitter occur due to the coupling with the antenna surface
plasmons in the spectral region from 4THz to 15THz. Our results show that the
radiation efficiency can be enhanced by four orders of magnitude and that the
quantum efficiency reaches values close to 0.8 when the emission frequency
coincides with one of the resonant dipolar frequencies. On the other hand,
these quantities can be reduced in a great measure at a specific frequency for
a given emitter location. We present calculations of the near-field
distribution and the far field intensity which reveal the role of the plasmonic
antenna resonance in the emitter enhanced radiation. We show that the spectral
region where the radiation is enhanced can be chosen over a wide range by
varying the chemical potential of graphene from 0.2eV to 1eV.
