Reexamination of entanglement of superpositions

Journal Article · Thu Nov 15 04:00:00 EST 2007 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.76.052320· OSTI ID:21027982

Gour, Gilad ^[1]

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1. Institute for Quantum Information Science and Department of Mathematics and Statistics, University of Calgary, 2500 University Drive NW, Calgary, Alberta, T2N 1N4 (Canada)

We find tight lower and upper bounds on the entanglement of a superposition of two bipartite states in terms of the entanglement of the two states constituting the superposition. Our upper bound is dramatically tighter than the one presented by Linden et al. [Phys. Rev. Lett. 97, 100502 (2006)] and our lower bound can be used to provide lower bounds on different measures of entanglement such as the entanglement of formation and the entanglement of subspaces. We also find that in the case in which the two states are one-sided orthogonal, the entanglement of the superposition state can be expressed explicitly in terms of the entanglement of the two states in the superposition.

• OSTI ID: 21027982
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 5 Vol. 76; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
INFORMATION THEORY
QUANTUM COMPUTERS
QUANTUM ENTANGLEMENT
QUANTUM INFORMATION
QUANTUM MECHANICS