Optimized oracle and diffusion operator implementations for enhanced quantum search performance

Abstract

Searching for an item in an unstructured database with Grover's search algorithm (GSA) guarantees a quadratic improvement in speed compared to classical approaches. One of the challenges in implementing GSA is the need for a large number of gates, which can be resource-intensive and error-prone. This paper presents a novel optimization of GSA that minimizes the complexity by reducing the gate count and circuit depth of the oracle and diffusion operator. A 47 % and 49 % reduction in gate count and circuit depth is observed for the 3-, 4-, and 5-qubit implementations of the optimized GSA against the standard version. Furthermore, the optimized GSA is utilized to perform a search in a quantum database for the index of $|111〉$. The results also indicate a significant improvement in the accuracy and execution time for the 3-, 4-, and 5-qubit implementations, and for searching a quantum database with the optimized GSA against the standard GSA.