Surface electronic structure of Mg(0001)

Mg(0001) has been studied with angle-resolved photoemission spectroscopy for photon energies in the range 7.0-26.8 eV. The polar-angle dependence of the photoelectron emission was recorded along the two symmetry lines ΓM̄ and ΓK̄ of the surface Brillouin zone. Six structures are identified in the spectra. Two sharp peaks are assigned to emission from surface states. One is located in a band gap around Γ, the other in a band gap near M̄. Three peaks are interpreted as indirect transitions from different electron pockets in the Brillouin zone. These regions with high densities of occupied states are located close to Γ, L, and K in the bulk Brillouin zone. Our experiments confirm earlier magnetoacoustic attenuation and de Haas---van Alphen experiments with respect to these electron pockets. Finally one broad structure is interpreted as a direct optical transition between bulk bands.