Angle-resolved photoemission intensities in a cuprate system with bilayer coupling: Effects of transition matrix elements and photoelectron losses

We have studied photoemission in the superconducting cuprate system with CuO₂ bilayer under the assumption that the valence hole is so localized that it looks similar to a core hole. Applying the assumption, one can calculate both intrinsic and extrinsic losses depending on the photon energy and the photohole position. We have found that the two layers suffering from different losses are so coupled that mixed losses may influence the photoemission spectra in accordance with the bonding and antibonding states due to the bilayer splitting. In the study, such a mixing between losses of the two layers is described incorporating the matrix element effects on the simplest level. Further, the photoemission intensity variations for bonding and antibonding symmetries as a function of the incident photon energies are evaluated and discussed.