Theory of an output coupler for Bose-Einstein condensed atoms

The evolution of a two component Bose-Einstein condensate, consisting of atoms in two distinct hyperfine states, is modeled using a generalization of the Gross-Pitaevskii equation. Coherent coupling of the components by a microwave or KF field gives rise to a range of spatiotemporal behaviors, controlled by the strength and detuning of the applied field. From an initial trapped single component state, a second component can be generated which may escape from the trapping region or remain trapped within the first component. The initiating mechanism is identified and characterized.