Auger Decay of Surface Rydberg State

Decay of the first Rydberg surface state on a metal surface is calculated in terms of Auger transitions between the electronic surface states. Using a three band model to describe the relevant surface band structure, the line width due to this surface Auger process is found to be about 8 times larger on the Ni(111) surface than on the Cu surface. This significant difference results from the difference in surface state occupancy. Comparison with recent experimental data from two photon photoemission demonstrates that these surface states are essential for the decay of the excited electron at surface