Propagation of an electromagnetic wave based on a continuum model of kp-type in an almost circular bundle of packed metal nanotubes

Abstract

A continuum model of kp-type for the approximate calculation of the characteristics of electromagnetic waves propagating in an almost circular (azimuthally symmetric), closely packed bundle of parallel, identical, and metal carbon nanotubes (CNTs) yields results in reasonably good agreement with the equivalent-multishell approach and with a many-body technique, for infinitely long bundles when the number of CNTs is moderately high. The slow-wave coefficients for azimuthally symmetric guided waves increase with the number of metallic CNTs in the bundle, tending for these bundles to unity, which is characteristic of macroscopic metallic wires. The existence of an azimuthally asymmetric guided wave at low frequencies in a bundle of a large number of finite-length CNTs stands in contrast to the characteristics of guided-wave propagation in a single CNT. A continuum model of kp-type yields the polarizability scalar and the antenna efficiency of a bundle of finite-length CNTs in the long-wavelength regime over a wide frequency range spanning the terahertz and the near-infrared regimes. Edge effects give rise to geometric resonances in such bundles. • The slow-wave coefficients for azimuthally symmetric directed waves. • The characteristics of electromagnetic waves propagating in an almost circular, bundle of carbon nanotubes (CNTs). • Contrast of characteristics of a guided-wave at low frequencies in a bundle of a large number of CNTs and in single CNT.