Plasma dynamics in graphite and SWNT probed by inelastic electron and X-ray scattering

Graphite as well as bundled and freestanding single-walled carbon nanotubes (SWNTs) are allotropes of sp² carbon. However their dynamical structure factor S (q, w) differs greatly because of the very different dimensionalities and geometries. Here S (q, w) is experimentally accessed by means of inelastic X-ray and electron scattering.In our combined approach we utilize the equivalency and complementarity of the two techniques to access the dispersion relation of electronic inter-band transitions across the entire Brillouin zone. The extended range plasmon dispersions provide direct insight into the imprints of macroscopic screening and low-dimensional confinement on plasmons in SWNTs.