Low-Temperature Scanning Tunnelling Spectroscopy

Using low-temperature scanning tunnelling microscopy we have investigated confinement of electronic surface states to hexagonal islands and other nanoscale structures on Ag(111). Local spectroscopy and spatial maps of the differential conductance are analyzed using simple models of the electronic structure. Moreover, we studied electron scattering from isolated Ce ad-atoms on Ag(111). dI/dV tunnelling spectra reveal a characteristic antiresonance around the Fermi energy which is interpreted a Fano interference between delocalized Ag states and the localized Kondo resonance.