Nonclassical Bose-Einstein condensate

A scheme for the generation of a nonclassical Bose-Einstein condensate is proposed in a J(g) = 1 --> J(e) = 0 system where ultracold atoms are populated in one ground-state sublevel \g-\ and form a Bose-Einstein condensate. By coupling the condensate to copropagating classical (sigma(-)) and quantum (sigma(+)) non-resonant travelling-wave laser fields, effective two-photon excitations between two ground-state sublevels \g-\ and \g(+)\ create a new condensate in \g(+)\. For an appropriate selection of the interaction time and atom-field coupling strengths, the quantum features of the quantized laser field, which may be prepared in a certain nonclassical state, can be exchanged with those of the quantum density field of the generated condensate.