Dominant gate imperfection in Grover's quantum search algorithm - art. no.042305

It is found Chat systematic errors in phase inversions and random errors in Hadmard-Walsh transformations are the dominant gate imperfection in Grover 's quantum search algorithm. They lead to reductions in the maximum probabi lity of the marked state and affect the efficiency of the algorithm. Given the degree of inaccuracy, we find that to guarantee a half-rate of success, the size of the database should be on the order of O(1/delta(2)), where de lta is the uncertainty.