Momentum-specified oxygen K resonant inelastic x-ray scattering for cuprates

The present study theoretically shows that oxygen K resonant inelastic X-ray scattering (O K RIXS) in cuprates gives momentum-resolved information on the occupied and unoccupied electronic states. By tuning the incident X-ray energy carefully, we can select the k point where the X-ray absorption process as well as the subsequent X-ray emission process actually takes place. The requirement for the momentum specification is that the core-hole potential effect in the intermediate state of the RIXS should be negligible. This requirement is fulfilled only for the O K RlXS in the case of cuprates.