Cyclotron resonance study of polarons in GaAs

Cyclotron resonance absorption and emission experiments have been performed under hot-electron conditions. Four different Landau-level transitions are observed. From the splitting of the cyclotron-resonance lines, polaron effects are determined. Different polaron theories are applied and their validity is discussed. An accurate treatment of polaron effects is found to be necessary for the determination of the band-edge effective mass, which is determined to be $m_0^{*}=0.0650m$.