Ferromagnetism of semiconducting structures with the indirect interaction of magnetic impurities through a quasi-two-dimensional conduction channel

Ferromagnetism in a layer of magnetic impurity atoms indirectly interacting through a quasi-two-dimensional conduction channel in the nearest quantum well is considered in the mean-field model. The interaction appears through the RKKY mechanism due to the extension of the wavefunction of charge carriers localized in a model triangular well to the region where the impurities are localized. The Curie temperature and its dependence on the carrier density in the well and well depth are determined. The results are compared with the experimental data concerning the structures based on the diluted magnetic semiconductors Ca_1−x Mn _x As.