  It is found that Grover's quantum search algorithm is not robust against
phase inversion and Hadmard transformation inaccuracies. Imperfect phase
inversions and Hadmard-Walsh transformations in Grover's quantum search
algorithm lead to reductions in the maximum probability of the marked state and
affect the efficiency of the algorithm. even in the absence of decoherence.
Given the degrees of inaccuracies, we find that to guarantee half rate of
success, the size of the database should be in the order of $O({1 \over
\delta^2})$, where $\delta$ is the uncertainty.
