A heuristic look at plasmon resonances in graphene nanodisks

Plasmon resonances in graphene nanodisks were analyzed by examining plasmon modes resulted from a boundary integral equation method applied to disks of finite thickness. The main resonance modes are identified for both electric field polarizations: parallel and perpendicular to the nanodisk plane. Using physical arguments resulted from our method we show: (a) the scaling of plasmon frequency with the diameter of the nanodisk for parallel polarization, and (b) the disappearance of the plasmon mode induced by fields with perpendicular polarization in the case of infinitesimally thin disks. Numerical calculations performed with our method agree very well with results obtained using commercial programs.