|Electronic states in self-assembled metallic nanostructures|
|Universidad del Pais Vasco - San Sebastian - Spain|
|Wednesday 23 May 2007 , 15h30|
|Talk at the workshop (2007)|
Nanostructured Au, Ag, and Cu noble metal surfaces are excellent playgrounds to realize self-assembled metallic nanostructures and probe their extended electronic states. Using angular photoemission, namely the sophisticated version of the photoelectric effect, we test surface electron bands in step arrays and dislocation networks. In step lattices, we observe 1D quantum well energy levels of electrons confined in terraces, and are able of probing their electron wave functions in a rather straightforward manner. The surface state dimensionality can be tuned by varying the density of steps. I will show different examples, which range from the clear-cut 1D and 2D cases observed in 1D step arrays with different lattice constant, to a mixture of 1D and 2D states in more complex faceted surfaces. 2D dislocation networks may exhibit Fermi surface nesting of the Shockley-type surface state. In such cases, the free-electron like band is modified around the Fermi energy, triggering the interplay between the geometry and the electronic structure. I will discuss such situation in two different systems.