Spin polarization of photoelectrons from solid cesium by circularly polarized light

The spin polarization of photoelectrons excited in cesium metal by circularly polarized light is discussed using group theoretical methods. Calculations of the spin polarization have been performed for direct transitions at the Γ-point and between Δ, Λ and Σ states. The results suggest that photoelectrons excited in monocrystalline Cs could have a high degree of spin polarization which depends both on the wave vector of the electrons and on the energy of the absorbed photon. Measurement of this polarization should allow the spin-orbit splitting of different energy bands to be determined.