  We analyze the optical quantum control of impurity spins in proximity to a
quantum dot. A laser pulse creates an exciton in the dot and controls the spins
by indirect coupling. We show how to determine the control parameters using as
an illustration the production of maximal spin entanglement. We consider errors
in the quantum control due to the exciton radiative recombination. The control
errors in the adiabatic and nonadiabatic case are compared to the threshold
needed for scalable quantum computing.
