Electron lifetime in armchair carbon nanotubes

Abstract

The excited conduction electrons in metallic armchair carbon nanotubes can decay by inelastic electron-electron scattering. The deexcitation channels include the single-particle and collective excitations of different angular momenta. The higher conduction subbands have more deexcitation channels, or shorter electron lifetimes. Each conduction subband has certain states with very long lifetimes, and a simple relationship between the inverse electron lifetime and the state energy is absent. Such results directly reflect the characteristics of the ID excitation spectra. The inverse electron lifetime contrasts sharply with those of semiconducting carbon nanotubes, graphite, and 2D and 3D metallic systems. Dimensionalities play an important role in the many-body effects. The predicted results could be verified by femtosecond time-resolved optical spectroscopy.