Influence of the Oscillating Electric Field on the Photodetachment of H- near a Metal Surface

Using the first order classical perturbation theory and the time-dependent closed orbit theory, we study the photodetachment of H- near a metal surface plus a weak oscillating electric field for the first time. The results show that the oscillating electric field can reduce the strength of the photodetachment cross section. The influence of the oscillating electric field is not only related to its strength, but also related to the distance from the ion to the metal surface. For a given ion-surface distance, with the increase of the strength of the oscillating electric field, the oscillating amplitude in the photodetachment cross section was decreased greatly. Besides, for a given oscillating electric field, with the increase of the ion-surface distance, its influence becomes much more obvious. As the ion-surface distance is very large, even a very weak oscillating electric field can weaken the photodetachment cross section of H (-) near a metal surface greatly. This study provides a new understanding on the photodetachment process of negative ion in the vicinity of surfaces and time-dependent electric field.