Exploring the optimal sensitivity of sum-variance nonseparability criteria for spin-1/2 systems
- Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627 (United States)
We report on experimental and theoretical studies on recently introduced entanglement measures which use a sum of spin-variance criteria for two spin-1/2 particles. Three inequalities are explored which exhibit useful concatenating properties. They are each shown to have greater sensitivities than a Bell's measurement, while each requiring fewer measurements than a Bell's measurement to obtain. The simplest inequality, requiring just four measurements, is shown to be efficient at testing for entanglement in down-conversion sources which naturally exhibit maximally polarized noise. The most complex inequality, requiring just 12 measurements, is shown to have a sensitivity equal to that of the Peres separability criterion for maximally polarized and Werner noise. This increased sensitivity implies optimality of the measure.
- OSTI ID:
- 20649922
- Journal Information:
- Physical Review. A, Vol. 70, Issue 6; Other Information: DOI: 10.1103/PhysRevA.70.062320; (c) 2004 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1050-2947
- Country of Publication:
- United States
- Language:
- English
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