Abstract
Frequency-dependent cyclotron-resonance measurements are reported on Ga0.47In0.53As-InP and Ga0.47In0.53As-Al0.48In0.52As heterojunctions. Discontinuities in the effective mass occur at two frequencies as a result of resonant polaron coupling with both optic-phonon modes present in the Ga0.47In0.53As alloy. The coupling occurs at the frequencies at the TO phonons, in contrast to measurements on bulk materials. Possible changes in the screening and polarization of the optic-phonon modes are considered. © 1985 The American Physical Society.