Electronic distribution and nonlinear optical response at the metal-electrolyte interface

Abstract
The potential and angular dependence of second-harmonic generation from a metal-electrolyte interface has been measured. The perpendicular surface contribution to the harmonic polarization is found to be significant and to vary in a characteristic manner with the surface charge induced by the electrolyte. Both the overall magnitude of the surface polarization and its variation with applied potential are reproduced qualitatively by microscopic calculations based on the time-dependent density-functional approach.