Electron cyclotron mass in undoped CdTe/CdMnTe quantum wells
  Optically detected cyclotron resonance of two-dimensional electrons has been studied in nominally undoped CdTe/(Cd,Mn)Te quantum wells. The enhancement of carrier quantum confinement results in an increase of the electron cyclotron mass from 0.099$m_0 $ to 0.112$m_0 $ with well width decreasing from 30 down to 3.6 nm. Model calculations of the electron effective mass have been performed for this material system and good agreement with experimental data is achieved for an electron-phonon coupling constant $\alpha $=0.32. 
A.A. Dremin, D.R. Yakovlev, A.A. Sirenko, S.I. Gubarev, O.P.   Shabelsky, A. Waag, M. Bayer