Author/Authors :
Grüneis، نويسنده , , A. and Saito، نويسنده , , R. and Jiang، نويسنده , , J. and Samsonidze، نويسنده , , Ge.G. and Pimenta، نويسنده , , M.A. and Jorio، نويسنده , , Carlos B. A. de Souza Filho، نويسنده , , A.G. and Dresselhaus، نويسنده , , G. and Dresselhaus، نويسنده , , M.S.، نويسنده ,
Abstract :
We calculated the resonance condition for the radial breathing Raman mode for single wall carbon nanotube (SWNT) bundles for light polarization parallel and perpendicular to the tube axis. The radial breathing modes that are not observed in isolated SWNTs, but are observed in SWNT bundles, are assigned to a resonance process for light with perpendicular polarization. Asymmetry between the valence and conduction π energy bands becomes essential for obtaining resonance conditions. We find that due to a high joint density of states, armchair SWNTs have the largest optical transition intensities.
