The invention discloses a
black box quantum state preparation method based on grouping
processing. The method comprises the steps that according to a mark bit and an initial
quantum state, a coarse proportion
estimation value of a target state is determined, and the initial
quantum state is a superposition state obtained by
processing an input
data vector based on a
black box. Under the condition that the coarse proportion
estimation value is smaller than a grouping threshold value, separation
processing is conducted on the initial
quantum state according to a first auxiliary bit, a first intermediate
quantum state is determined, the grouping threshold value is determined based on the number of input data vectors, the first intermediate
quantum state comprises a target state part and an orthogonal state part, the target state part comprises a first sub-quantum state, and the orthogonal state part comprises a second sub-quantum state; the orthogonal state portion includes a second sub-quantum state. And according to the first intermediate quantum state, determining a first fine proportion estimated value corresponding to the first sub-quantum state and a second fine proportion estimated value corresponding to the second sub-quantum state so as to realize quantum state preparation. In this way, quantum
amplitude amplification is prevented from being directly executed on overall data, and the
amplitude amplification times are reduced.