Parameters of the magnetic polaron state in diluted magnetic semiconductors Cd-Mn-Te with low manganese concentration

A method for the determination of magnetic polaron parameters is suggested for diluted magnetic semiconductors with low manganese concentration x, when the magnetic polaron shift of the exciton energy cannot be observed in practice. We show that the average exchange field, created by the localized exciton, and the magnetic polaron energy can be determined from the experimentally measured magnetic-field dependences of the circular polarization of the luminescence and Zeeman splitting of the free exciton. Theoretical dependences of the circular polarization on the magnetic field have been calculated in the two-dimensional case for different temperatures. Results of the calculations are in good agreement with our experimental data for CdTe/${\mathrm{Cd}}_{1\mathrm{-}\mathit{x}}$ ${\mathrm{Mn}}_{\mathit{x}}$Te quantum wells with x=0.117 and 0.13. © 1996 The American Physical Society.