Explanation for the “Apparent” Temperature and Density Dependence of the Optical Phonon Frequency in Heterostructures

Recent magneto-phonon resonance experiments on heterostructures suggest that the Electrons interact with longitudinal optical phonons with a frequency which is considerably smaller than in the corresponding bulk material. A mechanism is proposed here which produces the observed shift in the resonance position of the magneto-phonon spectra but which is nevertheless consistent with the interaction with the bulk optical phonon.