Speed-up and entanglement in quantum searching
Abstract
We investigate the issue of speed-up and the necessity of entanglement in Grover's quantum search algorithm. We find that in a pure state implementation of Grover's algorithm entanglement is present even though the initial and target states are product states. In pseudo-pure state implementations, the separability of the states involved defines an entanglement boundary in terms of a bound on the purity parameter. Using this bound we investigate the necessity of entanglement in quantum searching for these pseudo-pure state implementations. If every active molecule involved in the ensemble is `charged for' then in existing machines speed-up without entanglement is not possible.
Cite
@article{arxiv.quant-ph/0008018,
title = {Speed-up and entanglement in quantum searching},
author = {Samuel L. Braunstein and Arun K. Pati},
journal= {arXiv preprint arXiv:quant-ph/0008018},
year = {2007}
}
Comments
Latex file, no figures, 11 pages, Extended version, To appear in Journal QIC