Spin‐dependent dynamics of ultrafast polarised optical pulse propagation in coherent semiconductor quantum systems

A new model for rigorous theoretical description of circularly (elliptically) polarised ultrashort optical pulse interactions with the resonant nonlinearities in semiconductor optical waveguides is proposed. The method is based on self‐consistent solution in the time domain of the vector Maxwell equations coupled via microscopic polarisation to the coherent time‐evolution equations of a discrete N‐level quantum system in terms of the real pseudospin (coherence) vector. The model is initially applied to a generic two‐level quantum system and subsequently to a 4‐level system describing the heavy‐hole excitonic transitions in low‐dimensional semiconductor systems, such as quantum wells and quantum dots. Selective optical excitation of specific spin states by predefined helicity of the optical field in the linear regime and an onset of self‐induced transparency and polarised soliton formation in the nonlinear regime are numerically demonstrated in both discrete‐level systems. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)