All-Optical Coherent Control of Spin Dynamics in Semiconductor Quantum Dots

A new model for rigorous theoretical description of circularly (elliptically) polarized ultrashort optical pulse interactions with singly charged quantum dots embedded in semiconductor optical waveguides and microcavities is proposed. The method is based on self-consistent solution in the time domain of the vector Maxwell equations coupled via microscopic polarization to the coherent time-evolution equations of a discrete N-level quantum system in terms of the real pseudospin (coherence) vector. The model is applied to a 4-level system describing the optical dipole transitions of the trion state in a singly charged quantum dot. Selective optical excitation of specific spin states by predefined helicity of the optical field and an onset of self-induced transparency and polarized soliton formation in the nonlinear regime are numerically demonstrated