Resonant magneto-polarons in strongly-coupled superlattices

Impurity bound magneto-polarons are studied experimentally and theoretically in a strongly-coupled GaAs/AlGaAs superlattice. The 1s --> 2p+ transition of well-center donors is tuned through resonance with the GaAs optical phonon mode. An anti-level crossing behavior and three different peaks are clearly observed at the LO-phonon energy. The theoretical analysis shows that the size of the magneto-polaron effects: (1) is very close to those for the bulk system, and (2) no direct evidence is found for non bulk LO-phonon interaction.