Abstract:
For the Grover algorithm, we derive the exact formula of the norm of the amplitude in the marked state in a sine-function form and use this formula to derive the necessary and sufficient phase condition условие $\sin\Delta\leq|\beta|$ for this algorithm with arbitrary phase rotations. We show that the condition of identical rotation angles $\theta=\phi$, which is a special case of our condition, is a sufficient but not necessary phase condition.