PHOTOEMISSION INVESTIGATION OF THE RECONSTRUCTED AU(110) SURFACE

An sp type surface state has previously been reported at the YBAR point of the surface Brillouin zone of the Au(110) surface, and was associated with a gap in the calculated projected density of states of the unreconstructed surface occurring at the YBAR point of the (1x1) surface. More recent calculations, taking account of the true (1 x 2) structure of the surface, predict that there is no surface state at the YBAR point. We have carried out a detailed experimental investigation of the electronic structure of this system using angle-resolved photoemission excited by He I, Ne I and Ar I radiation and find no evidence for a surface state at the YBAR point, in accord with the calculations. A feature observed at the Fermi level with He I radiation is interpreted as photoemission from the d-band excited by He I beta-radiation. Features observed with Ne I and Ar I radiation in various parts of the Brillouin zone are interpreted as direct transitions in the bulk. This indicates that the reconstruction changes the electronic structure of the surface so that a surface state in the projection of the L gap does not occur.