  We show that spin-orbit coupling in a quantum dot molecule allows for
coherent manipulation of two electron spin states using Raman transitions. Such
two-electron spin states defined by the singlet and triplet states of two
exchange coupled quantum dots can have favorable coherence properties. In
addition, two of the four metastable ground states in this system can be used
as auxiliary states that could facilitate implementation of tasks such as
mapping of spin states to that of a single propagating photon. We find that
even weak spin-orbit effects -- manifesting themselves as slightly different
g-factors for the electron and the hole -- would allow for the coherent Raman
coupling of the singlet-triplet states. We also discuss the possibilities for
implementing quantum optical techniques for spin preparation and manipulation.
