Surface plasmon polaritons in double-walled carbon nanotubes

The dispersion characteristics of surface plasmon polaritons in double-walled carbon nanotubes have been studied, taking into account ohmic losses. A dispersion equation in matrix form is obtained for the SPPs taking into account the anisotropy of the electrical conductivity of the nanotube walls. Its numerical solutions are found for low-order plasmonic modes propagating over a wide frequency range (including THz and the visible region). It was found that for double-walled carbon nanotubes of large radii, the surface plasmon polaritons retardation coefficient can exceed 300.