Ultrafast vibrational energy transfer in carbon nanotube

Ying Kuan Ko¹, Atsushi Yabushita^1,2*, Yui Konno³, Yutaka Maeda³, Takayoshi Kobayashi¹

¹Department of Electrophysics, National YangMing ChiaoTung University, Hsinchu, Taiwan
²Research Institute of Engineering, Kanagawa University, Kanagawa, Japan
³Department of Chemistry, Tokyo Gakugei University, Tokyo, Japan

* Presenter:Atsushi Yabushita, email:yabushita@nycu.edu.tw

Previously, we have reported our experimental result showing a vibrational frequency shift in a carbon nanotube (CNT) sample. One of the possible mechanisms which can cause the frequency shift is vibrational energy transfer between CNTs whose chiralities are different to each other. However, we could not deny the other possible mechanism caused by the frequency difference between the electronic ground state and the electronic excited state.
In the present work , we have prepared a CNT sample which only contains (6,5) chirality to perform its ultrafast spectroscopy. The result was compared with that for a CNT sample which contains mixture of various chiralities. The vibrational frequency shift was observed only in the CNT sample with various chiralities, which indicates that the observed frequency shift is caused by the vibrational energy transfer between the different chiralities.

Keywords: ultrafast spectroscopy, carbon nanotube, vibrational dynamics