Spin Flip Raman Scattering in Cadmium Sulfide

The Raman scattering with which this paper deals[1] is due to neutral donor and acceptor impurities in CdS. In this hexagonal crystal, both the usual neutral donors and acceptors have a spin degeneracy of 2 which is lifted by the application of a magnetic field. In the presence of a magnetic field H, an electronic Raman scattering can take place in which the electron or hole begins in one magnetic state, and is left in the other, the change of photon energy being ± μH. We will indicate why this unlikely-sounding process has the observed large scattering cross section, and examine some details of the geometry, field, and energy dependence of the cross section.