Magneto infrared absorption and polaron coupling in high electron density GaAs quantum well

We investigated the cyclotron resonance (CR) on a series of samples containing high-density 2DEG (7.4–View the MathML source) in GaAs/AlAs single quantum wells (in high magnetic fields up to View the MathML source) in order to study the resonant polaron coupling. We did not observe any anomalies of the CR peakʹs evolution around the longitudinal optical (LO) phonon energy of GaAs View the MathML source. Instead, a pinning of the CR peak occurs near the transverse optical (TO) phonon energy and is accompanied by an increase of the width and of the intensity of the peak. We have simulated the transmission of the whole structure using a multilayer dielectric model, which allows us to determine the correct values of the relaxation frequency and its variation with magnetic field. We discuss the different possibilities of the coupling observed around the TO energy.