Multiparticle entanglement and the Schrodinger cat state using ground-state coherences

In this paper we show how ground-state coherences and dispersive interactions of single photons with a collective system produces a variety of multiparticle entangled states and mesoscopic superpositions. Further single photons act as a carrier of information and can entangle macroscopic systems and can produce large phase shifts. Our work produces states as considered by Schrodinger in the cat-paradox, though in our case cat is replaced by the collective atomic system.