Fine Structure of Excitons in Quantum Wires

The fine structure of the localized exciton ground state is studied in GaAs/AlAs quantum wires. Polarization of photoluminescence under the polarized excitation and spin-flip Raman scattering versus external magnetic field were measured. Exciton longitudinal g-factor and values of the level splitting due to anisotropic exchange interaction were determined. The exchange splitting values δ2 of optically active states and the distribution of split dipole in their directions can be probed optically.