Quasi-one-dimensional quantized states in an epitaxial ag film on a one-dimensional surface superstructure

The in-plane energy dispersion of quantized states in an ultrathin Ag film formed on the one-dimensional (1D) surface superstructure Si(111)-(4x1)-In shows clear 1D anisotropy instead of the isotropic two-dimensional free-electron-like behavior expected for an isolated metal film. The present photoemission results demonstrate that an atomic layer at the film-substrate interface can regulate the dimensionality of electron motion in quantum films.