Measurement Of The Infrared Transmission Through A Single Doped Gaas Quantum Well In An External Magnetic Field: Evidence For Polaron Effects

Precise absolute far-infrared magnetotransmission experiments have been performed in magnetic fields up to 33 T on a series of single GaAs quantum wells doped at different levels. The transmission spectra have been simulated with a multilayer dielectric model. The imaginary part of the optical response function which reveals singular features related to the electron-phonon interactions has been extracted. In addition to the expected polaronic effects due to the longitudinal-optical phonon of GaAs, a kind of carrier-concentration-dependent interaction with interface phonons is observed. A simple physical model is used to try to quantify these interactions and explore their origin.