Field Purification in the intensity-dependent Jaynes-Cummings model
  We have found that, in the intensity-dependent Jaynes-Cummings model, a field initially prepared in a statistical mixture of two coherent states, $|\alpha>$ and $|-\alpha>$, evolves toward a pure state. We have also shown that an even-coherent state turns periodically a into rotated odd-coherent state during the evolution. 
D.S. Freitas, A. Vidiella-Barranco, and J.A. Roversi (Universidade   Estadual de Campinas, SP, Brazil)