2004, Kluwer Academic Publishers. By a transformation to a rotating reference system, a nuclear level mixing scheme is equivalent to a scheme with pure quadrupole splitting and a strong RF-drive between quadrupole split lines. It is shown that this scheme is similar to the one used in optics in which electromagnetically induced transparency (EIT) and low group velocity have been demonstrated. One can therefore consider the slowing down of gamma photons. However, with gamma photons one always works with single photons and the question remains whether the concept of group velocity can be applied.