Surface state quasiparticle dynamics at metal surfaces

Abstract

Theoretical investigations on the dynamics of noble metal surface state quasiparticles are presented in this article. Decay processes of electrons and holes are mainly determined by the electron–electron (e–e) and electron–phonon (e–ph) interaction. The latter predominates at energies close to the Fermi level. The e–e interaction is treated within a many-body GW self-energy approach. The phonon-induced decay rate is studied by taking into account, in principle, all electron and phonon states, including surface states, and a linearly screened pseudopotential. These formalisms have been applied to the case of Au(111) surface state holes. The total linewidth has been calculated as a function of binding energy. Our results indicate that, for electron–electron interactions, the main decay channel for surface state holes is the decay into the surface band itself (intraband transitions). Interband transitions predominate in the case of electron–phonon interaction.