@inproceedings{f5ed6397e4b9480e841c1f632a7d089d,
title = "Ultrafast changes in the far-infrared conductivity of carbon nanotubes",
abstract = "The ultrafast charge-carrier dynamics in single-wall carbon nanotubes (NTs) have been investigated by time-resolved THz spectroscopy. Both the equilibrium and non-equilibrium conductivity data of the NTs in the far-infrared (FIR) spectral range from 1 to 40 THz are dominated by optical transitions across the band gap of tubes with gap energies of ∼ 10 meV. A simple model based on an ensemble of two-level systems excellently explains all experimental findings. In particular, the surprisingly weak temperature dependence of the FIR conductivity has been shown to arise from tube-to-tube variation of the chemical potential which is ∼ 100 meV in our sample. The results strongly suggest to use the temperature dependence of the FIR conductivity as a very sensitive and contact-free probe of the NT sample purity. Finally, the relaxation of the photo-excited NT sheet on a picosecond time scale mainly reflects the cooling of hot phonons which is about five times faster than in graphite. This points to much stronger lattice anharmonicities in NTs.",
author = "C. Frischkorn and T. Kampfrath and \{Von Volkmann\}, K. and L. Perfetti and M. Wolf",
year = "2008",
month = dec,
day = "31",
doi = "10.1109/ICIMW.2008.4665509",
language = "English",
isbn = "9781424421206",
series = "33rd International Conference on Infrared and Millimeter Waves and the 16th International Conference on Terahertz Electronics, 2008, IRMMW-THz 2008",
booktitle = "33rd International Conference on Infrared and Millimeter Waves and the 16th International Conference on Terahertz Electronics, 2008, IRMMW-THz 2008",
note = "33rd International Conference on Infrared and Millimeter Waves and the 16th International Conference on Terahertz Electronics, 2008, IRMMW-THz 2008 ; Conference date: 15-09-2008 Through 19-09-2008",
}