Energies and lifetimes of atomic Rydberg states near metal surfaces

The energy shifts and broadenings of atomic Rydberg states have been calculated as a function of distance from a metal surface using the complex scaling technique. The results of this calculation show a relatively complicated distance dependence of the energy shifts and broadenings of the levels near the surface. Some of the orbitals hybridize with each other, resulting in states with wave functions that differ strongly in their orientation with respect to the surface. The widths of the states oriented toward the metal an found to be many orders of magnitude broader than the states oriented toward the vacuum. The widths of some states exhibit a nonexponential dependence on atom-surface separation. It is shown that for an accurate description of the interaction of Rydberg atoms with metal surfaces it is important to employ a realistic surface potential.