2007/07/10 by Pranaw Rungta, Rungta, Pranaw
Computer Science · Physics and Astronomy · #Computability, Logic, AI Algorithms #FOS: Physical sciences #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum Physics (quant-ph) #quant-ph
paper · pdf · doi:10.48550/arxiv.0707.1410
23 pages, 2 figures
arxiv created 2007/07/10 · openalex publication_date 2007/07/10 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We analyze the role played by entanglement in the dynamical evolution of Grover's search algorithm in the space of qubits. We show that the algorithm can be equivalently described as an iterative change of the entanglement between the qubits, which governs the evolution of the initial state towards the target state, and where the entanglement can be quantified in terms a single entanglement monotone. We also provide a necessary and sufficient condition for the quadratic speedup, which illustrates how the change in the bipartite entanglement of the state after each iteration determines the corresponding increase in the probability of finding the target state. This allows us to reestablish from the entanglement perspective that Grover's search algorithm is the only optimal pure state search algorithm.