  Experiments in coherent spectroscopy correspond to control of quantum
mechanical ensembles guiding them from initial to final target states by
unitary transformations. The control inputs (pulse sequences) that accomplish
these unitary transformations should take as little time as possible so as to
minimize the effects of relaxation and to optimize the sensitivity of the
experiments. Here, we present a radically different and generally applicable
approach to efficient control of dynamics in spin chains of arbitrary length.
The approach relies on the creation of localized spin waves, ``spin solitons'',
and efficient propagation of these soliton states through the spin chain. The
methods presented are expected to find immediate applications in control of
spin dynamics in coherent spectroscopy and quantum information processing.
