Two-dimensional exciton magnetic polaron dynamics in thin CdTe/(Cd,Mn)Te quantum wells

Dynamics of the two-dimensional exciton magnetic polaron (EMP) formation in thin CdTe/Cd0.79Mn0.21Te quantum wells is analyzed on the base of solving the non- stationary Schroedinger equation with the time dependent exchange potential and measured by time-resolved spectroscopy. The magnetic polaron formation time is found to enhance dramatically with an increase of the QW width, Lz, to exceed the exciton life-time at Lz > 10 angstroms and to suppress the observed polaron energy shift at Lz > 25 angstroms. Analyzing the effect of the initial exciton localization due to Lz fluctuations on the magnetic polaron formation we conclude that EMP can be considered as quasi-free. The EMP formation is shown to be governed by the in-plane exciton magnetic autolocalization.