Photodetachment of H- near a Dielectric-Covered Metal Surface

We combine a simple model potential with closed-orbit theory to study the photodetachment of H- near a dielectric-covered metal surface. We calculate photodetachment cross sections to show that the chemisorption of a dielectric thin layer on the metal surface can significantly affect the photodetachment of negative ions. Compared to the photodetachment of hydrogen negative ions near clean metallic surfaces, our calculated cross sections show stronger oscillations, the amplitude of the oscillation growing with the layer thickness. For fixed thickness, the amplitude depends on the dielectric constant and on the metallic surface. We expect our study to guide future experimental studies of negative-ion photodetachment from dielectric-covered metallic surfaces.