Coherent dynamics of magnetoexcitons in semiconductor nanorings

The coherent dynamics of magnetoexcitons in semiconductor nanorings followi ng pulsed optical excitation is studied. The calculated temporal evolution of the excitonic dipole moment may be understood as a superposition of the relative motion of electrons and holes and a global circular motion associa ted with tile magnetic-field splitting of these states. This dynamics of th e electron-hole pairs can be generated either by local optical excitation o f art ordered ring or, alternatively, by homogeneous: excitation of rings w ith broken rotational symmetry due to disorder or band tilting.