Reconstruction-induced multiple gaps in the weak coupling limit: The surface bands of Au(111) vicinal surfaces

The opening of several gaps in the surface band structure of vicinal Au(23 23 21) surfaces has been shown by high-resolution photoemission spectroscopy, and the energy dependence of the surface electron density has been determined by scanning tunneling spectroscopy. From a methodological point of view, the values of the gaps and the phase of the electronic density allow an estimation of the reconstruction potential, which yields the electronic Bragg diffraction, the gap formation, and the modulation of the electron density. These spectroscopic behaviors give a pedagogical illustration of one of the basic concepts of solid state physics.