Probing the Graphite Band Structure with Resonant Soft-X-Ray Fluorescence

For incident photon energies near the core binding energy, inelastic x-ray scattering theory predicts a coherent absorption-emission process in which crystal momentum is conserved. Momentum conservation should manifest itself as dispersive features in fluorescence spectra. We report the detection of such features for the first time in graphite, and show that there exists a clear relationship between them and the graphite band structure. Our results demonstrate the potential of resonant soft-x-ray fluorescence for examining the momentum-resolved electronic structure of complex materials.