Abstract
We have performed SH spectroscopy on a reconstructed Au (100) 5 ×20 surface. We have found a broad SH intensity continuum for the SH photon energy from 2hω= 2.2 to 4.2 eV. The SH intensity in the Sin/Pout (s-polarized input and p-polarized output) polarization configuration is higher than that in Pin/Pout polarization configuration between the photon energies 2hω = 3.7 and 4.2 eV. However this inequality was reversed when the surface was exposed to air. Thus, the SH response in this photon energy region is attributed to surface electronic states. The observed broadness of the structures in the SH intensity spectra may be attributed to the dispersion of the surface electronic states caused by the increased interactions among the localized d-electrons on the Au reconstructed surface.
