Coherent Phonon Coupled with Exciton in Semiconducting Single-walled Carbon Nanotubes with Several Chiralities

Dynamics of coherent phonon coupled with exciton in single-walled carbon nanotubes (SWNTs) are investigated by using few cycle pulse laser. Modulations corresponding to the radial breathing mode (RBM) observed in the time traces for the four chiral systems have been analyzed. The vibrational modes of the coherent phonon spectra are identified from the 2D distribution of probe photon energy versus Fourier frequency. Resonance conditions and mode frequencies lead to definite chirality assignments. The present study clarifies that the observed probe photon energy dependence of RBM amplitude is due to both the imaginary and real parts of the third-order susceptibility.