Impurity-bound magnetopolarons in confined structures

A systematic study of the well-width dependence (between 125 and 450 Å) of electron-optical-phonon interactions in GaAs/AlGaAs multiple-quantum-wells is described. The 1s-2p₊ transition of well-center donors has been tuned through resonances with GaAs optical phonons by magnetic fields up to 23.5 T and followed with far infrared photoconductivity spectroscopy. Extremely large and asymmetric interaction gaps have been observed in both the two-level and three-level resonance regions for small well-width samples; these gaps decrease systematically asthe well-width increases, indicating weaker interactions for larger well-width samples.