  We used continuous wave photoluminescence (cw-PL) and time resolved
photoluminescence (TR-PL) spectroscopy to compare the properties of magnetic
polarons (MP) in two related spatially indirect II-VI epitaxially grown quantum
dot systems. In the ZnTe/(Zn,Mn)Se system the holes are confined in the
non-magnetic ZnTe quantum dots (QDs), and the electrons reside in the magnetic
(Zn,Mn)Se matrix. On the other hand, in the (Zn,Mn)Te/ZnSe system, the holes
are confined in the magnetic (Zn,Mn)Te QDs, while the electrons remain in the
surrounding non-magnetic ZnSe matrix. The magnetic polaron formation energies
in both systems were measured from the temporal red-shift of the band-edge
emission. The magnetic polaron exhibits distinct characteristics depending on
the location of the Mn ions. In the ZnTe/(Zn,Mn)Se system the magnetic polaron
shows conventional behavior with decreasing with increasing temperature T and
increasing magnetic field B. In contrast, in the (Zn,Mn)Te/ZnSe system has
unconventional dependence on temperature T and magnetic field B; is weakly
dependent on T as well as on B. We discuss a possible origin for such a
striking difference in the MP properties in two closely related QD systems.
