A regular step, a dislocation slip step and a step formed by the emergence of a split edge dislocation to the surface influence the local density of states close to the onset of the surface state as investigated by scanning tunnelling spectroscopy at low temperatures. The onset of the surface state shifts close to the regular step and the dislocation slip step by approximately 15meV towards the Fermi energy. Additional maxima above the onset were only observed if a second step led to confinement. In both cases, the conductivity decreased close to the step. However, an increase in conductance above the surface state onset was observed close to the split edge dislocation step. Furthermore, a variety of additional states were discernable. Thus, different types of steps lead to markedly different changes in the local electronic structure on surfaces.

Spatial Variation of the Surface State Onset Close to Three Types of Surface Steps on Ag(111) Studied by Scanning Tunnelling Spectroscopy. S.Heidorn, K.Morgenstern: New Journal of Physics, 2011, 13[3], 033034