  Recent measurements of coherent electron spin dynamics reveal an
antiferromagnetic s-d exchange coupling between conduction band electrons and
electrons localized on Mn{2+} impurities in GaMnAs quantum wells. Here we
discuss systematic measurements of the s-d exchange interaction in
GaMnAs/AlGaAs quantum wells with different confinement potentials using
time-resolved Kerr rotation. Extending previous investigations of the
dependence of the s-d exchange, N{0}alpha, on well width, we find that its
magnitude also depends on well depth. Both phenomena reduce to a general
dependence on confinement energy, described by a band-mixing model of
confinement-induced kinetic exchange in the conduction band.
