Quasistatic resonance of a chemical potential interruption in a graphene layer and its polarizability: The mixed-polarity semilocalized plasmon

The chemical potential of a graphene layer can be locally interrupted by electrostatic gating or chemical doping. When properly designed, electrically small local interruption can possess quasistatic resonance and be strongly excited by electromagnetic field. This excitation generates a mixed-type semilocalized plasmon wave, e.g., it launches TM mode within the interruption domain and TE modes into the surrounding layer. Since the resonance is quasistatic, it is essentially independent of the interruption size and it exists also for sizes much smaller than the corresponding wavelengths of the aforementioned modes. Furthermore, the interruption's polarizability can be defined and calculated. Unlike the conventional polarizability, which is defined directly via a particle's dipole response, here it is defined via the induced currents in the interruption and in its surrounding. We verify our results by comparing them to full-wave numerical simulations. The results have potential applications in many one-atom-thick metamaterials and devices.