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 (σ^-) and quantum (σ⁺) 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.