  We show theoretically and experimentally the existence of a new quantum
interference(QI) effect between the electron-hole interactions and the
scattering by a single Mn impurity. Theoretical model, including
electron-valence hole correlations, the short and long range exchange
interaction of Mn ion with the heavy hole and with electron and anisotropy of
the quantum dot, is compared with photoluminescence spectroscopy of CdTe dots
with single magnetic ions. We show how design of the electronic levels of a
quantum dot enable the design of an exciton, control of the quantum
interference and hence engineering of light-Mn interaction.
