Quantum holography and multiparticle entanglement using ground-state   coherences
  A method of storing and retrieving quantum states of radiation fields using the ground-state coherences is discussed. We demonstrate the generation of multiparticle entangled states starting from atoms prepared in a coherent state. Use is made of the j=-1/2 to +1/2 atomic transition and its interaction with a far-detuned elliptically polarized field. 
G. S. Agarwal, P. Lougovski, H. Walther