Implementing nonlocal gates with nonmaximally entangled states

Journal Article · Tue Mar 01 04:00:00 EST 2005 · Physical Review. A

DOI:https://doi.org/10.1103/PhysRevA.71.032322· OSTI ID:20650360

Groisman, Berry ^[1]; Reznik, Benni ^[2]

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1. HH Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol, BS8 1TL (United Kingdom)
2. School of Physics and Astronomy, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 69978 (Israel)

We propose and study a method for using nonmaximally entangled states to probabilistically implement desired nonlocal gates. Unlike distillation-based protocols, this method does not generate a maximally entangled state at intermediate stages of the process. As a consequence, the method becomes more efficient at a certain range of parameters. Gates of the form exp[i{xi}{sigma}{sub n{sub A}}{sigma}{sub n{sub B}}] with {xi}<<1 can be implemented with nearly unit probability and with vanishingly small entanglement, while for the distillation-based method, the gate is produced with a vanishing success probability. We also derive an upper bound to the optimal success probability and show that, in the small-entanglement limit, the bound is tight.

• OSTI ID: 20650360
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 3 Vol. 71; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

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