The role of surface states in the Na/Cu(110)(1x2) reconstruction

Reflection anisotropy spectroscopy (RAS) is combined with scanning tunnelling microscopy in a study of the Na/Cu(110)(1x2) surface reconstruction induced on the thermally roughened Cu(110) surface. The roughening transition of Cu(110) generates a surface morphology consisting of a high density of exclusively monatomic height steps. This surface is further characterized by the irreversible loss of the 2.1 eV RAS feature and an enhancement in the response around 4 eV. Na deposition onto the roughened surface results in the formation of the (1x2) reconstruction. We show that the occupancy of the surface state near the Fermi level at Y-bar on Cu(110) is not a prerequisite for surface reconstruction. (author)