Magnetic Ions in Studies of Semiconductor Quantum Well Structures

A few aspects of a relation between magnetic properties of Mn ion system and electronic states confined in CdTe based quantum wells are discussed. It is shown that the influence of the magnetic fluctuations on the states confined in the quantum well results in the reduction of the relative valence band offset with temperature. Also the decrease in the effective Zeeman splitting is observed by a modulation technique at high temperatures and is explained in terms of the modification of the selection rules for an exciton localised in thermal fluctuations. For the p-doped samples the giant Zeeman splitting is used to tune the polarization of a hole gas by a small magnetic field. The "competition-like" relation between the oscillator strength of exciton (X) and positive trion (X$\text{}^{+}$) is proved experimentally.