Two dimensional magnetophonon resonance in GaInAsInP superlattices

Cyclotron resonance and magnetophonon resonance studies have been made of superlattices grown from thin layers of Ga.₄₇In.₅₃As and InP, which exhibit two dimensional behaviour at temperatures up to 250K. The electron effective mass varies with layer thickness in reasonable agreement with the calculated non-parabolicity. The LO phonon energies are calculated from magnetophonon oscillations and mass values obtained from cyclotron resonance. A strong series of oscillations results from the dominant 'GaAs-like' mode in GaInAs. A second, weaker series corresponds to the energy of the InP LO phonon. This is evidence for a long range phonon interaction, with the field of the phonons extending into the GaInAs to cause a significant coupling with the electrons bound in the quantum wells.