Plasmon satellites in core-level photoemission

Abstract

The apparent suppression of plasmon satellites in core-level photoemission at low electron kinetic energy is studied. The process of photoemission is studied in the Golden Rule formulation, and the final-state wavefunction corresponding to the photoemitted electron leaving a plasmon excited in the solid is found using perturbation theory. It is found that interference between intrinsic and extrinsic excitation suppresses the long-wavelength surface and bulk plasmon excitation, but the shorter-wavelength plasmons are still excited even at low electron kinetic energies. However the satellites are featureless and are probably lost in the background until the electron kinetic energy is about 40 eV, with parameters appropriate to Al. Subtracting the featureless 'background', total satellite intensities of 14% for the surface plasmons and 31% for the bulk plasmons are obtained, at an electron kinetic energy of 100 eV.