Circular dichroism in the angular distribution of core photoelectrons from Si(001): A photoelectron-diffraction analysis

Circular dichroism has by now been observed experimentally in the angular distributions of core photoelectrons from both adsorbed molecules and atoms in single-crystal substrates. Photoelectron-diffraction theory provides a general method for predicting and analyzing such effects, as we demonstrate here by applying it to such dichroism in a nonmagnetic single crystal: Si 2s and 2p emission from Si(001), as studied experimentally by Daimon et al. [Jpn. J. Appl. Phys. 32, L1480 (1993)]. Our calculations correctly predict the apparent rotation of certain major diffraction features with right and left circularly polarized light, and also provide a more quantitative approach to analyzing such data than a previously proposed model based upon considerations of forward-scattering effects in photoelectron excitation.