Theory of Time-Resolved Two-Photon Photoemission from a Metal Surface: the Effect of Coulomb Interactions between Electrons

Abstract

The effect of Coulomb interactions between electrons on time-resolved two-photon photoemission from a metal surface is investigated theoretically. It is shown by nonequilibrium perturbation theory that the correlation trace (photoelectron intensity as a function of the pump-probe delay time) depends on lifetimes of both photoexcited electrons and holes due to the effect of Coulomb interactions. The numerical results of the correlation trace reproduce the qualitative features of the experimental results.