Electron-Phonon Interaction in Single-Wall Carbon Nanotubes: A Time-Domain Study

We investigate the electron-phonon $\left(e-\mathrm{ph}\right)$ interaction in single-wall carbon nanotube samples at room temperature using femtosecond time-resolved photoemission. By probing electrons from the vicinity of the Fermi level we are able to study the $e-\mathrm{ph}$ interaction in the metallic nanotube species only. The observed electron dynamics can be used to calculate $e-\mathrm{ph}$ scattering matrix elements for two likely scattering scenarios: forward scattering from twistons and backscattering by longitudinal acoustic phonons. The corresponding matrix elements reveal an intrinsically weak $e-\mathrm{ph}$ interaction approximately $50\%$ smaller than predicted by tight-binding calculations.