  Processes of association in an atomic Bose-Einstein condensate, and
dissociation of the resulting molecular condensate, due to Feshbach resonance
in a time-dependent magnetic field, are analyzed incorporating non-mean-field
quantum corrections and inelastic collisions. Calculations for the Na atomic
condensate demonstrate that there exist optimal conditions under which about
80% of the atomic population can be converted to a relatively long-lived
molecular condensate (with lifetimes of 10 ms and more). Entangled atoms in
two-mode squeezed states (with noise reduction of about 30 dB) may also be
formed by molecular dissociation. A gas of atoms in squeezed or entangled
states can have applications in quantum computing, communications, and
measurements.
