PHOTOEMISSION AS A PROBE OF ELECTRONIC STATES IN ULTRATHIN MAGNETIC OVERLAYERS - CORRELATION AND HYBRIDIZATION EFFECTS

We examine the fundamental roles of the d-d correlation and s-d hybridization in determining the electronic structure, as probed by photoemission (PE), of one monolayer of Co on Cu(001). We show that the interface hybridization between the electrons in narrow (Co d) and wide (Cu s) bands can induce significant changes to features driven by correlation effects in the PE spectrum (PES). An exact diagonalization approach using and going beyond single-particle results is employed in the calculation. We conclude that it is crucial to include both the d -d correlation and the s-d hybridization in a many-body model for understanding and interpreting the PES. Calculated results are compared with available experimental data.