Excitonic effects on radial breathing mode intensity of single wall carbon nanotubes

We develop exciton–photon and exciton–phonon interaction matrix elements for single wall carbon nanotubes within extended tight binding method. The exciton–photon matrix elements using the extended tight binding wave function have a large chirality dependence compared with the previous calculation by simple tight binding method. Using the exciton–photon and exciton–phonon matrix elements presented here, we calculate resonance Raman intensity for radial breathing mode as a function of diameter and chiral angle. Excitonic effect of resonance Raman intensities for the radial breathing mode is enhanced by the curvature and trigonal warping effects.