Evidence for the decay of surface plasmons into one-electron excitations has been obtained in photoemission measurements from a slightly roughened surface of aluminum. A simple theory has been developed which explains the resultant photoyield in terms of both the drop in reflectance resulting from roughness-aided plasmon coupling, and the relative penetration depth of the fields associated with these excited plasmons.

• Received 23 October 1969

DOI:https://doi.org/10.1103/PhysRevLett.24.64