Electronic structure of reconstructed Au(100): Two-dimensional and one-dimensional surface states

The clean surface of Au(100) presents a complex reconstruction characterized by a hexagonal topmost layer. We report an angle-resolved photoemission study of the electronic structure of this surface, including an analysis of the Fermi surface, combined with structural information from low-energy electron diffraction and scanning tunneling microscopy. In the complex Fermi surface map found, we identify different contributions from the bulk bands, from interface states located below the hexagonal topmost layer, and from the hexagonal topmost layer itself. The electronic states related to this layer exhibit quasi-one-dimensional character, in agreement with the chain aspect of the reconstructed layer, as demonstrated by their dispersion, periodicity, and reciprocal space location.