Ultrafast exciton dephasing in semiconducting single-walled carbon nanotubes.
Femtosecond two-pulse degenerate four-wave mixing spectroscopy was applied to study the exciton dephasing in a broad range of excitation intensities and lattice temperatures. We find that both exciton-exciton and exciton-phonon scattering have profound effects on the dephasing process. The dominant phonon mode involved in the dephasing is identified as the out-of-plane, transverse optical mode with a frequency of 847 cm(-1). The extracted homogeneous linewidths at all measured temperatures are in excellent agreement with the results of a single-tube photoluminescence experiment.
Ma
Ying-Zhong
YZ
Department of Chemistry, University of California, Berkeley, California 94720-1460, USA.
Graham
Matthew W
MW
Fleming
Graham R
GR
Green
Alexander A
AA
Hersam
Mark C
MC