  We apply the previously developed theory of the resonant indirect exchange
interaction to explain the ferromagnetic properties of the hybrid
heterostructure consisting of a InGaAs-based quantum well (QW) sandwiched
between GaAs barriers with a remote Mn delta-layer. The experimentally obtained
dependence of the Curie temperature on the QW depth exhibits a maximum related
to the region of resonant indirect exchange. We suggest the theoretical
explanantion and a fit to this dependence as a result of the two contributions
to ferromagnetism - the intralayer contribution and the resonant exchange
contribution provided by the QW.
