aiqbench analysis
This paper addresses a critical limitation in Grover's algorithm by introducing a deterministic quantum search method that guarantees success regardless of the initial probability distribution. By requiring at most one additional iteration, it maintains quadratic speedup over classical approaches while enabling exact searches for multiple target states within bounded steps. The work provides a complete circuit-level implementation, offering practical utility for applications where probabilistic failure is unacceptable in large-scale unstructured search problems.
Deterministic Quantum Search for Arbitrary Initial Success Probabilities
arXiv:2505.15512v2 Announce Type: replace Abstract: Unstructured search remains one of the significant challenges in computer science, as classical search algorithms become increasingly impractical for large-scale systems due to their linear time complexity. Quantum algorithms, notably Grover's algorithm, leverage quantum parallelism to achieve quadratic speedup over classical approaches. Its generalization, the amplitude amplification algorithm, extends this advantage to a broader class of search problems. However, both algorithms are inherently probabilistic and fail to guarantee success with certainty, also under the standard implementation of these algorithms, they offer no quantum advantage when the initial success probability exceeds 0.5. This work presents a deterministic quantum search algorithm that operates effectively for arbitrary initial success probabilities, providing guaranteed success in searching target states. The proposed approach introduces at most one additional iteration beyond the optimal count required by probabilistic quantum search algorithms. The algorithm preserves the quadratic speedup characteristic of quantum search methods. Additionally, an approach is proposed for the exact search of multiple target states within a bounded number of steps. A complete circuit-level implementation of the proposed algorithm is also presented.
Abstract:Unstructured search remains one of the significant challenges in computer science, as classical search algorithms become increasingly impractical for large-scale systems due to their linear time complexity. Quantum algorithms, notably Grover's algorithm, leverage quantum parallelism to achieve quadratic speedup over classical approaches. Its generalization, the amplitude amplification algorithm, extends this advantage to a broader class of search problems. However, both algorithms are inherently probabilistic and fail to guarantee success with certainty, also under the standard implementation of these algorithms, they offer no quantum advantage when the initial success probability exceeds 0.5. This work presents a deterministic quantum search algorithm that operates effectively for arbitrary initial success probabilities, providing guaranteed success in searching target states. The proposed approach introduces at most one additional iteration beyond the optimal count required by probabilistic quantum search algorithms. The algorithm preserves the quadratic speedup characteristic of quantum search methods. Additionally, an approach is proposed for the exact search of multiple target states within a bounded number of steps. A complete circuit-level implementation of the proposed algorithm is also presented.
arXiv:2505.15512 [quant-ph]
(or arXiv:2505.15512v2 [quant-ph] for this version)
Mishra, Harishankar, Asvija Balasubramanyam, and Gudapati Naresh Raghava. "Deterministic quantum search for arbitrary initial success probabilities." Quantum Information Processing 25.7 (2026): 222
https://doi.org/10.1007/s11128-026-05246-6 DOI(s) linking to related resources
Full text under the publisher's open licence · 210 words
Related coverage
Lattice-Based Cryptography Explained
Quantum Zeitgeist · Aug 15, 2026
Entanglement swap now yields the same state every time
Quantum Zeitgeist · Aug 28, 2026
Game Design Creativity evals
LessWrong · Oct 12, 2026
Superconducting Quantum Materials and Systems (SQMS) Center: Researchers Extend Grover’s Search to More Efficient Multilevel Quantum Systems
Quantum Zeitgeist · Jul 29, 2026