Angle-resolved photoemission and the electronic structure of Pd(111)

Abstract

A theoretical study of various models which are commonly used for the analysis of angle-resolved photoemission is reported. For the example of the Pd(111) surface we discuss the quality and justification of these models. We have calculated the ${\overrightarrow{\mathrm{k}}}_{\parallel }$-resolved surface and bulk densities of states and the band structure of occupied and unoccupied states. Furthermore, we have calculated photoemission spectra within the one-step approach. These theoretical spectra reproduce the main features and trends of the experimental data. We find that the ${\overrightarrow{\mathrm{k}}}_{\parallel }$-resolved densities of states are, in general, not reflected in the photoemission. The spectra can only be interpreted in a modified direct-transition model where the influence of the inelastic electron-electron interaction in the final state is taken into account.