Spin Polarization of Atomic and Molecular Photoelectrons

Abstract

Publisher Summary This chapter discusses the spin polarization effects in atomic and molecular photoelectrons. Photoelectron polarization measurements give qualitatively new information on atomic structure and, being combined with the usually measured partial photoionization cross section and angular distribution of photoelectrons allow a complete quantum-mechanical experiment to be performed. This chapter reviews the theory of polarization phenomena in the photoionization of atoms and molecules. The theoretical predictions are compared with existing experimental results. Some future prospects of polarization investigations are also discussed. For the complete quantum-mechanical description of a photoionization process, it is necessary to find the probability of ejection of electrons in a given direction K with the spin oriented in some other directions (K and s are the unit vectors). Photoelectrons are spin-polarized in the direction perpendicular to the scattering plane for absorption of unpolarized light and have all three components of polarization for absorption of circularly polarized and linearly polarized light. Photoionization of atoms allows producing a beam of highly spin-polarized electrons. Moreover, angle- and spin-resolved photoelectron spectroscopy gives the data for the most exhaustive comparison of first-principle theories with experiment.