Combined Exciton-Cyclotron Resonance in Quantum Well Structures

A combined exciton-cyclotron resonance is found in photoluminescence excitation and reflectivity spectra of semiconductor quantum wells containing an electron gas of low density. In external magnetic fields, an incident photon creates an exciton in the ground state and simultaneously excites one of the resident electrons from the lowest to one of the upper Landau levels. A theoretical model is developed, which gives a good quantitative description of the energy position and the intensity of the combined exciton-cyclotron resonance.