LINEAR AND NONLINEAR RESPONSE OF STEPPED METAL-SURFACES TO A STATIC ELECTRIC-FIELD

The linear and non-linear response of vicinal metal surfaces to a stat ic electric field oriented normal to the surface is studied by perform ing self-consistent density functional calculations. Regularly stepped jellium surfaces corresponding to the electron density of Al are used to model these surfaces. The normal component of the polarization vec tor associated with the non-linear-induced charge is increased relativ e to that of a flat jellium surface in proportion to the step density up to very high densities. However, the magnitude of this enhancement amounts to only approximately 15% at maximum.