We use a method to probe experimentally the probability density of carriers
confined in semiconductor quantum structures. The exciton Zeeman splitting
in quantum wells containing a single, ultranarrow magnetic layer is studie
d depending on the layer position. In particular, a system consisting of a
1/4 monolayer MnTe embedded at varying positions in nonmagnetic CdTe/CdMgTe
quantum wells is investigated. The sp-d exchange interaction results in a
drastic increase of the Zeeman splitting, which, because of the strongly lo
calized nature of this interaction, sensitively depends on the position of
the MnTe submonolayer in the quantum well. For various interband transition
s we show that the dependence of the exciton Zeeman splitting on the positi
on of the magnetic layer directly maps the probability density of free hole
s in the growth direction.