  Despite the advent of Grover's algorithm for the unstructured search, its
successful implementation on near-term quantum devices is still limited. We
apply three strategies to reduce the errors associated with implementing
quantum search algorithms. Our improved search algorithms have been implemented
on the IBM quantum processors. Using them, we demonstrate three- and four-qubit
search algorithm with higher average success probabilities compared to previous
works. We present the successful execution of the five-qubit search on the IBM
quantum processor for the first time. The results have been benchmarked using
degraded ratio, which is the ratio between the experimental and the theoretical
success probabilities. The fast decay of the degraded ratio supports our
divide-and-conquer strategy. Our proposed strategies are also useful for
implementation of quantum search algorithms in the post-NISQ era.
