Above-threshold photoelectric effect at a metal
Zaretskii D. F. , Nersesov E. A.
A multiphoton photoelectric effect at a metal in an intense laser field is analyzed. The light is propagating along the surface of the metal. An interpretation is offered for the above-threshold peaks in the spectrum of photoelectrons. The Coulomb interaction of these electrons with the image potential of the electron cloud in the metal is taken into account in this interpretation. The observed electron spectrum can be explained on the basis of a multiple scattering of an electron by the image potential, with a field photon being captured in each scattering event. It is also shown that the above-threshold peaks arise in fields far weaker than the corresponding fields in the case of atoms (in above-threshold ionization).