Polaron cyclotron resonance in II–VI compounds at high magnetic fields

Abstract In this paper, we discuss the cyclotron resonance in II–VI compounds in very high magnetic fields, in particular, those in CdS where many different anomalies were observed in high magnetic fields. High magnetic fields enable us to observe clean cyclotron resonance spectra even in low mobility crystals, thus in most II–VI semiconductors we can study the polaron effect up to the high energy range well above the LO phonon energy. Resonant polaron effect is observed prominently and we can estimate the electron–phonon coupling strength from the magnitude of the anticrossing effect. In addition to the resonant polaron interaction, it was found that cyclotron effective mass shows a peculiar temperature dependence which is explained theoretically by the combination of the electron‐phonon interaction and the impurity scattering.