Raman Scattering from Spin — Density Fluctuations in n — Ga As

摘要: The anomalously large cross sections observed for scattering from single-electron excitations in GaAs can be explained part as spin-density fluctuations. electromagnetic field is coupled to the spins through second-order p∙ A perturbation terms involving spin-orbit splitting of valence band. At high carrier densities, where screening wave vector much greater than momentum transfer, spindensity fluctuations are not screened out charge-density are, and hence section larger that due alone. polarization properties scattered radiation also different two processes. For matrix element proportional \(\overrightarrow {\sigma \cdot } {\mkern 1mu} \left( {{{\hat \in }_1} \times {{\hat }_2}} \right),\) whereas it varies \(\left( }_1}\cdot \({\hat _1}\) _2}\) incident vectors. magnetic taken zero throughout.