Observation of long-wavelength interface phonons in a GaAs/AlGaAs superlattice

We report on the first observation of long-wavelength interface optical phonons in a GaAs/AlGaAs superlattice by high-resolution electron-energy-loss spectroscopy. The observed spectrum is well accounted for by scattering theory with material data taken from infrared spectroscopy. © 1986 The American Physical Society.