Auger, resonant, and plasmon-assisted charge-transfer processes in atom-surface collisions

M.A. VICENTE ALVAREZ; V. H. PONCE; E. C. GOLDBERG

PHYSICAL REVIEW B - CONDENSED MATTER AND MATERIALS PHYSICS

American Physical Society

Lugar: New York; Año: 1998 vol. 57 p. 14919 - 14929

0163-1829

The Keldysh-Green function formalism is used to evaluate the atomic occupation number of a projectile colliding with a metal surface. This formalism has an advantage that allows us to handle simultaneously Auger, resonant, and plasmon-assisted exchange processes along with the interference between them. A timedependent Hamiltonian containing Auger-like and resonant-like terms, and the electron-electron Coulomb potential in the solid, is proposed. The atomic self-energies are calculated up to a second order in the interaction potential. An effective resonant amplitude is defined, and Auger self-energies are presented where the plasmon-assisted processes are included through a surface response function. Finally, some numerical results for a proton colliding with an Al surface by using a simplified description of the solid response function are presented, where an analysis in terms of the incidence angle and the energy level is shown.