Quantitative electron momentum spectroscopy of aluminum films

We present measurements of the spectral momentum density of aluminum films and compare these results with two different theories. One theory is a standard band structure calculation, taking into account the lattice potential; the other theory neglects the lattice potential, but takes electron-electron correlations approximately into account. Near the Fermi level, the band structure calculations and jellium-type many-body calculations provide satisfactory results, especially if multiple scattering effects are taken into account. The measured intensity at binding energies exceeding the single-particle band width is too large, even after correction for multiple scattering effects for the band structure calculations. The jellium-type many-body calculations have more intensity than the band structure-type calculations at higher binding energies. However the sharp satellite features present in this theory are not observed in the experiment.