Electromagnetic scattering from finite-length metallic carbon nanotubes in the lower IR bands

A model is presented for electromagnetic scattering from infinite planar arrays of finite-length metallic carbon nanotubes, and isolated nanotubes, in the lower IR bands. The scattered field is predicted using a semiclassical formulation based on a periodic Green's function for the array, and a quantum conductance function for the carbon nanotubes. The finite length of the tubes is accounted for electromagnetically by imposing a boundary condition on the tube ends. Scattering characteristics are investigated for various armchair carbon nanotube array configurations, as well as for isolated nanotubes. The principle observations of this study are that longitudinal (end-to-end) coupling between carbon nanotubes is not very important, although transverse (side-to-side) coupling in an array environment shifts and broadens resonance line shapes compared to the isolated tube case. Nanotube length and radius also play critical roles in governing scattering characteristics.