  The superpositional wave function oscillations for finite-time implementation
of quantum algorithms modifies the desired interference required for quantum
computing. We propose a scheme with trapped ultracold ion-pairs being qubits to
diminish the detrimental effect of the wave function oscillations, and apply
the scheme to the two-qubit Grover's search. It can be also found that the
qubits in our scheme are more robust against the decoherence caused by the
environment, and the model is scalable.
