Photoemission from (110) Faces of Noble Metals: Observation of One-Dimensional Density of States

Photoelectron distribution curves of (110) single-crystal faces of the noble metals Cu, Ag, and Au obtained at photon energies of 16.85 and 21.22 eV show strong contributions which cannot be accounted for by direct $k$-conserving transitions. Instead we observed a surprisingly good correlation between the measured spectra and the one-dimensional density of states of the bulk band structure. It is supposed that surface photoemission is responsible for the observed effect.