DICHROISM IN-CORE PHOTOELECTRON DIFFRACTION SPECTRA OF SI(001) AND DEPENDENCE ON THE PHOTON POLARIZATION

Photoelectron diffraction patterns of Si 2p core photoelectrons from S i(001) excited by photons of circular, elliptical and linear polarizat ions are calculated and compared with some experimental results. In ac cordance with the symmetry of the Si(001) sample, relations are derive d for the total intensity, the dichroism, and the spin polarization on the azimuthal angle. These relations on one hand describe the observe d different peak positions in the patterns for right and left, circula rly polarized radiation, and on the other hand provide information on the degree of polarization of the light.