Electron correlation effects in the spectral momentum density of graphite - art. no. 033108

The spectral function of an annealed evaporated carbon film was measured us ing a high-energy (e,2e) spectrometer. Interpretation of these data was rel atively straightforward due to low levels of multiple scattering. Large lif etime broadening and strong asymmetries were found in the observed line sha pes, with tails extending to large binding energies. A conventional band-st ructure calculation within the frame of the density functional theory faile d to describe the observed intensity. However it could be described well us ing a calculation of the spectral function based on the cumulant expansion to the single-particle Green's function. Neither the theory nor the experim ent showed indications of well-defined intrinsic plasmon structures.