Ionization of Rydberg atoms at metallic surfaces: Influence of stray fields

The ionization of xenon Rydberg atoms at metallic surfaces is examined. The data show that, when the effects of stray electric patch fields present on the surface are taken into account, ionization is well described by a simple over-the-barrier model. The patch fields are determined from direct measurements of the potential variations across the target surfaces using Kelvin probe force microscopy. Monte Carlo techniques are used to model the atom-surface interaction. The results confirm the important role that patch fields can play during Rydberg atom-surface interactions and suggest that such interactions can provide a sensitive probe of stray fields at surfaces.