  Raman excited spin coherences were experimentally observed in N-V diamond
color centers via nondegenerate four-wave mixing (NDFWM) and
electromagnetically induced transparency (EIT). The maximal absorption
suppression was found to be 17%, which corresponds to 70% of what is possible
given the random geometric orientation of the N-V center in diamond. In the
context of quantum computing in solids, this level of transparency represents
the efficient preparation of quantum bits (qubits), as well as ability to
perform arbitrary single qubit rotations.
