Surface Plasmon Polaritons Propagation Along Armchair and Zigzag Single-Wall Carbon Nanotubes With Different Radii

In this paper, we have studied chirality dependent optical properties of single-wall carbon nanotubes (CNTs), such as dynamic conductance and permittivity functions in THz, IR, and optical telecommunication bands. It is observed that CNTs with different radii yield different permittivity functions. We have presented the effects of phenomenological relaxation frequency, longitudinal surface plasmon resonance, and hybridization of π-orbitals on optical traits of armchair and zigzag CNTs. After their characterization, single-wall CNTs are utilized for guiding plasmonic surface modes, each is frequency dependent on its geometrical dimensions. It is demonstrated that surface plasmon polaritons can be excited along metallic nanotubes with very small radii. It is also revealed that as one choose the nanotube with smaller radius the propagation length and surface plasma frequency of that nanotube increase. The confinement of these modes and also their propagation length are studied and it is found that CNTs could become an excellent candidate for ultrathin plasmonic waveguides.