High Magnetic Field Effect on Exciton Energies in CdTe/Cd1-xMnxTe Quantum Wells Grown by MBE

The magneto-optical studies were performed through the transmission measurement on a series of CdTe/Cd1-xMnxTe multiple quantum wells with Mn contents of about 14% under pulsed magnetic fields up to 45 T. Observed absorption peaks of the heavy-hole and light-hole excitons show large Zeeman splitting due to the exchange interaction with Mn2+ spins in the barrier layer. Further, the observation of a series of Landau level transitions between the conduction and heavy-hole bands gives an estimate of the excitonic binding energy at 11–22 meV depending on the well width. The calculation based on the effective-mass approximation reveals that the hole states under magnetic fields exhibit complicated features due to the valence-band mixture and the strong sp-d exchange interaction. Calculated results of the interband transition energies and intensities were compared with the observations and help for their understanding.