Entanglement measures for intermediate separability of quantum states
- High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801 (Japan)
We present a family of entanglement measures R{sub m} which act as indicators of separability of n-qubit quantum states into m subsystems for arbitrary 2{<=}m{<=}n. The measure R{sub m} vanishes if the state is separable into m subsystems, and for m=n it gives the Meyer-Wallach measure, while for m=2 it reduces, in effect, to the one introduced recently by Love et al. [Quantum Inf. Process. 6, 187 (2007)]. The measures R{sub m} are evaluated explicitly for the Greenberger-Horne-Zeilinger state and the W state (and its modifications, the W{sub k} or Dicke states) to show that these globally entangled states exhibit rather distinct behaviors under the measures, indicating the utility of the measures R{sub m} for characterizing globally entangled states as well.
- OSTI ID:
- 21300815
- Journal Information:
- Physical Review. A, Vol. 79, Issue 5; Other Information: DOI: 10.1103/PhysRevA.79.052307; (c) 2009 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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