Interplay between plasmons and the band structure for the Mo(112) surface

Abstract

Recent photoemission and inverse photoemission results for the Mo(112) surface are discussed in the framework of the calculated band structure. For the Mo(112) surface, the main photoemission features combine contributions from both the surface and the bulk. Except for those photon energies near to excitations of the bulk and multipole surface plasmons, the comparison of the bulk band structure, along the k points normal to the surface, shows a good agreement with photoemission spectra in the position of the critical points. The dominant surface states at $\overline{\ensuremath{\Gamma}}$ are found to have the ${a}_{1}$ symmetry, while the band along $\overline{\ensuremath{\Gamma}}\ensuremath{-}\overline{Y}$ at about 0.8 eV binding energy is found to be odd with respect to the $\overline{\ensuremath{\Gamma}}\ensuremath{-}\overline{X}$ mirror plane. The surface-induced enhancement of photoemission---the surface photoeffect---is indicated and is shown to be responsible for dramatic changes in the spectra when the photon energy falls into the region of the multipole surface plasmons.