Direct measurement of the lifetime of optical phonons in single-walled carbon nanotubes.
Time-resolved anti-Stokes Raman spectroscopy has been applied to probe the dynamics of optical phonons created in single-walled carbon nanotubes by femtosecond laser excitation. From measurement of the decay of the anti-Stokes Raman signal in semiconducting nanotubes of (6,5) chiral index, a room-temperature lifetime for G-mode phonons of 1.1+/-0.2 ps has been determined. This lifetime, which reflects the anharmonic coupling of the G-mode phonons to lower-frequency phonons, is important in assessing the role of nonequilibrium phonon populations in high-field transport phenomena.
Song
Daohua
D
Department of Physics and Electrical Engineering, Columbia University, New York, New York 10027, USA.
Wang
Feng
F
Dukovic
Gordana
G
Zheng
M
M
Semke
E D
ED
Brus
Louis E
LE
Heinz
Tony F
TF