Complex frequencies and field distributions of localized surface plasmon modes in graphene-coated subwavelength wires

MAURO CUEVAS; MAXIMO RISO; RICARDO A. DEPINE

JOURNAL OF QUANTITATIVE SPECTROSCOPY AND RADIATIVE TRANSFER

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2016 vol. 173 p. 26 - 33

0022-4073

In this work we study the modal characteristics of localized surface plasmons in graphene-coated,circular cross-section wires. Localized surface plasmons are represented interms of cylindrical multipole partial waves characterized by discrete, complex frequenciesthat depend on the size of the wire and can be dynamically tuned via a gatevoltage. We consider both intrinsically nonplasmonic wires and intrinsically plasmonicwires. In the first case the localized surface plasmons are introduced by the graphenecoating, whereas in the second case the localized eigenmodes of the graphene coating areexpected to hybridize those already existing in the bare wire. We show that the approachpresented here, valid for particle sizes where the retardation effects can be significant, isin good agreement with analytical expressions obtained in the limit when particle size isvery small compared to the wavelength of the eigenmode and with results indirectlydetermined from scattering cross-section spectra