Bound magnetic polarons in semimagnetic quantum wells

We examine the position dependence of the binding energy of a hydrogenic impurity in a semimagnetic quantum well. We consider in particular, a CdTe well confined by (Cd,Mn)Te potential barriers. We show that, due to the penetration of the impurity wave function inside the barrier, at low temperatures, the exchange interaction with the Mn local spins may lead to the formation of a bound magnetic polaron. In such a case, the impurity is more strongly bound at the interface than at the center of the well, in contrast to the situation in nonmagnetic quantum wells.