Optical phonon lifetimes in single-walled carbon nanotubes by time-resolved Raman scattering.

The lifetimes of optical phonons (OPs) in single-walled carbon nanotubes are determined by time-resolved incoherent anti-Stokes Raman scattering using a subpicosecond pump-probe method. Lifetimes in semiconducting and metallic nanotubes at room temperature are similar, 1.2 and 0.9 ps, respectively. The OP lifetimes decrease with increasing temperature, approximately scaling as approximately 1/T, consistent with anharmonic processes being the dominant decay mechanism for both semiconducting and metallic nanotubes.