OPTICAL AND MAGNETOOPTICAL PROPERTIES OF CARBON NANOTUBE BUNDLES

The optical and magneto-optical properties of carbon nanotube bundles have been studied theoretically. The dielectric and magneto-dielectric functions in the long wavelength limit are calculated from the gradie nt approximation. A prominent pi-plasmon structure at similar to 6-7 e V is identified in the electron-energy-loss spectrum. The pi plasmon a lso reveals itself in the reflectance spectrum as a weak but sharp pla smon edge at similar to 6-7 eV. The detailed optical spectra depend on the polarization direction of the incident light, the nanotube struct ure (such as radius, chiral angle, and number of shells), and the magn etic flux through nanotubes. In general, carbon nanotube bundles would maintain the pi-plasmon frequency at similar to 6-7 eV. This is mainl y a consequence of the unique pi-band structure of the graphitelike sy stem. The magnetoreflectance spectra would exhibit a strongly periodic al oscillation during the variation of magnetic flux.