  We demonstrate that two coupled Bose-Einstein condensates (BEC) at zero
temperature can be used to realize a qubit which is the counterpart of
Josephson charge qubits. The two BEC are weakly coupled and confined in an
asymmetric double-well trap. When the "charging energy" of the system is much
larger than the Josephson energy and the system is biased near a degeneracy
point, the two BEC represent a qubit with two states differing only by one
atom. The realization of the BEC qubits in realistic BEC experiments is briefly
discussed.
