Theory of Carbon Nanotubes as Optical Nano Waveguides

Afshin Moradi

doi:10.4236/jemaa.2010.212088

Abstract

The propagation of surface plasmon waves in metallic single-walled carbon nanotubes is analyzed within the frame-work of the classical electrodynamics. The conduction electrons of the system are modelled by an in?nitesimally thin layer of free-electron gas which is described by means of the semiclassical kinetic theory of the electron dynamics. The effects of the energy band structure is taken into account and a more accurate dispersion relation for surface plasmon oscillations in the zig-zag and armchair nanotubes of metallic character is obtained.

Highlights

With the discovery by Iijima [1] of carbon nanotubes (CNTs) structures, a new class of materials with a reduced dimensionality has been introduced
By using the classical electrodynamics and a semiclassical kinetic theory, Slepyan et al [2], derived the dispersion relation of surface waves in single-walled carbon nanotubes (SWCNTs) and for the first time, found that CNTs can be used as a nano waveguide for controlling electro magnetic wave propagation in specified frequency ranges
In this Letter, we study the energy band effects on the dispersion relation of the surface plasmon waves in SWCNTs of metallic character, by using the semiclassical kinetic theory of the electron dynamics

Summary

Introduction

With the discovery by Iijima [1] of carbon nanotubes (CNTs) structures, a new class of materials with a reduced dimensionality has been introduced. Metallic CNTs are considered suitable candidates in the field of plasmonics as new plasmonics waveguides [2,3,4,5,6,7,8,9,10,11,12]. The hydrodynamic theory, without any effects of the energy band structure to be taken into account, can not be valid enough for the investigations of plasmon waves propagation in CNTs. SWCNTs are quasi one-dimensional material, which could be regarded as a rolled-up graphene layer (i.e., a mono-atomic layer of graphite) in the cylindrical form. SWCNTs are quasi one-dimensional material, which could be regarded as a rolled-up graphene layer (i.e., a mono-atomic layer of graphite) in the cylindrical form It has a radius of a few nanometers and lengths up to centimeters. The nanotubes with n 0 are called zig-zag, those with m n are called armchair and those with m n are called chiral

Formulation of the Problem

Conclusions