The Double-Layer Graphene Surface Plasmon-Polaritons Spectrum in Hydrodynamic Model

Abstract

The spectrum of surface plasmon polaritons in double-layer graphene with and without an external magnetic field by utilizing Maxwell’s equations in a hydrodynamic model was studied and field configurations were analyzed. There is neither a transverse magnetic (TM) mode nor a transverse electric (TE) mode but a full-field mode under the external field. Regardless of the presence or absence of an external field, the excited transverse magnetic field is symmetrical in the acoustic branch, whereas it is antisymmetrical in the optical branch. Meanwhile, the excited transverse electric field has opposite symmetry properties against to that of the transverse magnetic field. The results indicate that the rise of the spectrum is dominated by an external magnetic field in the infrared region and a non-local effect in the ultraviolet region. The influence of the layer distance on the spectrum was also studied.