Photoemission Footprints Of Extrinsic Plasmarons

A prediction of how to experimentally distinguish excitations of extrinsic plasmarons from intrinsic plasmarons is presented. In surface systems where excitations of acoustic surface plasmons are possible, it is shown that the photoelectron yield in normal photoemission should decay according to an inverse square-root dependence with respect to the photon energy. A computational analysis of the system p(2x2)-K/graphite confirms this prediction.