Inelastic electron scattering from a helical potential: transverse polarization and the structure factor in the single scattering approximation

Abstract

We analyze single scattering of unpolarized photoelectrons through a monolayer of chiral molecules modeled by a continuous hardcore helix and spin–orbit coupling. The molecular helix is represented by an optical contact potential containing a non-hermitian component describing inelastic events. Transmitted photoelectrons are transversely polarized at optimal angles, and separated into up and down spin with up to 20% efficiency. Such a process involves the interference of both spin–orbit and inelastic strengths, that are parameterized quantitatively to recent experiments in chiral self-assembled monolayers (SAMs). The structure factor of the model chiral molecule shows the energy dependence of the differential cross section which decays strongly as energy increases. Larger incident momenta reduce axial deviations from the forward direction and the spin–orbit interaction becomes less effective. Transverse electron polarization is then restricted to a characteristic energy window.