Interaction Time Dependence of Electron Tunneling Processes between an Atom and a Surface

Results of a study of electron transfer processes in the interaction of fluorine and hydrogen with Ag(111) are reported for a wide range of interaction times. For long interaction times the yield of H^-, resulting from resonant electron exchange, is larger than expected for a jelliumlike metal surface with a similar work function. For short interaction times, the yields follow the trend for jelliumlike surfaces. These results confirm the predictions of the theoretical work [Borisov et al. Phys. Rev. Lett. 80, 1996 (1998)] on electron transfer on surfaces with an L band gap. In the case of F^-, significant effects were, however, not observed.