Nonclassical Bose-Einstein condensate

A scheme is proposed to manipulate the quantum-statistical properties of a neutral atomic Bose-Einstein condensate in an ultracold alkali-atom-trap system with atoms in the ground hyperfine F=1, MF=±1,0 states (labeled respectively as g±,0). Initially, the atomic condensate is assumed to be prepared in a hyperfine sublevel g-. By effective two-photon excitations with two classical (σ-) and quantum (σ+) nonresonant copropagating traveling-wave light fields, we show that the atomic system can be settled into a coherent superposition of two atomic Bose-Einstein condensates corresponding to different ground hyperfine sublevels and different quantum statistics. Furthermore, with an appropriate choice of interaction time, atom-field coupling strengths, and quantum features of the quantized laser field, a nonclassical condensate can be prepared in the hyperfine sublevel g+.