Different contributions to spin polarization in the Auger neutralization of He+ ions at the Ni (111) surface under the influence of screening length

Abstract

Theoretical aspects are presented for the spin polarization of electrons excited during the impact of spin-polarized He+ ions on a Ni (111) surface. The screening length effects due to the screened Coulomb (Yukawa) potential on spin polarization are explored within the framework of spin-dependent Auger neutralization process. First-order perturbation theory is used to calculate the Auger rates. The incident He+ ions and the metal electrons are spin-polarized so that we will analyze the spin of empty bound state of He+ ions by two possibilities. One is that the spin of empty bound state is parallel to the majority spin in the metal electrons, and the other is that the spin of empty bound state is parallel to the minority spin in the metal electrons. Results are discussed depending on the spin-dependent matrix elements and the neutralization probability of He+ ions with different contributions.