抄録
A theory of light scattering in a magnetic metal using the spin-dependent electric polarizability is developed and is applied to Raman scattering by magnons in heavy rare earth metals. An important mechanism for one- and two-magnon scatterings arises from the coupling of radiation field with the 4f localized moments via spin-orbit interaction. There are also indirect mechanisms in which electric polarizability of the conduction electrons are modulated by the s–f exchange interaction. Contributions of these mechanisms to the spin-dependent polarizability are estimated. We present calculations of the scattering symmetries and intensities for one- and two-magnon processes in systems with ferro-magnetic, spiral and conical spin structures, with application to Tb and Dy, assuming the first mechanism is predominant. In the cases of spiral and conical structures the magnons with wave vectors ±k0 and ±2k0 are excited, where k0 is the wave vector describing the periodicity of the static spin arrangement.
