Optical spin orientation in crystals with diamond structure

Abstract

In a new type of photoemission experiment, spin orientation of the photoelectrons is achieved by the optical excitation process. The spin polarization depends only on the symmetry of the states involved. In this paper the method of optical spin orientation is applied to electronic states belonging to the important nonsymmorphic space group of the diamond lattice. Tables of Clebsch-Gordan coefficients at the special symmetry points $X$ and $W$ and symmetry line $Z$ of the Brillouin zone are given. They contain the necessary information to derive the spin polarization. For the other parts of the Brillouin zone it is shown that the already published tables for the point groups are applicable.