Selective coherent phonon mode generation in single wall carbon nanotubes

Ahmad R. T. Nugraha, Eddwi H. Hasdeo, Riichiro Saito

Published 2016-05-10Version 1

The ultrafast pulse-train technique is theoretically investigated to enhance a specific coherent phonon mode while suppressing the other phonon modes generated in single wall carbon nanotubes (SWNTs). In particular, we focus on the selectivity of the radial breathing mode (RBM) and the G-band for a given SWNT. We find that if the repetition period matches with integer multiple of the RBM phonon period, the RBM amplitude could be enhanced while the amplitudes of the other modes amplitudes are suppressed. As for the G-band, when we apply a repetition rate of half-integer multiple of the RBM period, the RBM could be suppressed because of destructive interference, while the G-band still survives. It is also possible to keep the G-band and suppress the RBM by applying a repetition rate that matches with integer multiple of the G-band phonon period. However, in this case we have to use a large number of laser pulses.