Local Invariants and Pairwise Entanglement in Symmetric Multi-qubit System

Abstract

Pairwise entanglement properties of a symmetric multi-qubit system are analyzed through a complete set of two-qubit local invariants. Collective features of entanglement, such as spin squeezing, are expressed in terms of invariants and a classifcation scheme for pairwise entanglement is proposed. The invariant criteria given here are shown to be related to the recently proposed (Phys. Rev. Lett. 95, 120502 (2005)) generalized spin squeezing inequalities for pairwise entanglement in symmetric multi-qubit states.

9 pages, 2 figures, REVTEX, Replaced with a published version

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Cited by in corpus (12)

• Constraints on the uncertainties of entangled symmetric qubits
• Collective multipole-like signatures of entanglement in symmetric N-qubit systems
• Separability of a family of one parameter W and GHZ multiqubit states using Abe-Rajagopal q-conditional entropy approach
• Practical schemes for the measurement of angular-momentum covariance matrices in quantum optics
• Spin squeezing in symmetric multiqubit states with two distinct Majorana spinors
• Equivalence of classicality and separability based on P phase-space representation of symmetric multiqubit states
• Characterizing nonlocality of pure symmetric three-qubit states
• Spin squeezing in Dicke-class of states with non-orthogonal spinors
• Quantification of Quantum Entanglement in a Multiparticle System of Two-Level Atoms Interacting with a Squeezed Vacuum State of the Radiation Field
• A total measure of multi-particle quantum correlations in atomic Schrödinger cat states
• Local sum uncertainty relations for angular momentum operators of bipartite permutation symmetric systems
• Lorentz invariants of pure three-qubit states