Spin quantum beats in semiconductors

Spin quantum-beat spectroscopy is presented as a powerful tool for the investigation of the electron Landé g factor and the spin dynamics in bulk and low-dimensional semiconductors. The technique has several advantages including high sensitivity, broad applicability, and ease of implementation and, therefore, proves to be superior to other techniques as, e.g., the Hanle-effect, spin-flip Raman scattering, and conduction band spin-resonance. We demonstrate the utility of this technique by the study of the temperature dependence of the electron Landé g factor g* in GaAs up to room temperature. We present as well results on the temperature dependence of g* in InP, the dependence of g* on quantum film thickness in GaAs-AlGaAs heterostructures, and the anisotropy of g* in quantum films and wires. A modification of this technique yields the direction of the spin rotation, i.e., the sign of g*. Finally, recent results on spin quantum beats in microcavities will be presented.