Non-local properties of a symmetric two-qubit system

Abstract

Non-local properties of symmetric two-qubit states are quantified in terms of a complete set of entanglement invariants. We prove that negative values of some of the invariants are signatures of quantum entanglement. This leads us to identify sufficient conditions for non-separability in terms of entanglement invariants. Non-local properties of two-qubit states extracted from (i) Dicke state (ii) state generated by one-axis twisting Hamiltonian, and (iii) one-dimensional Ising chain with nearest neighbour interaction are analyzed in terms of the invariants characterizing them.

5 pages, no figures

References in corpus (5)

• Separability Criterion for Density Matrices
• Nonlocal properties of two-qubit gates and mixed states and optimization of quantum computations
• Non-local properties of multi-particle density matrices
• On local invariants of pure three-qubit states
• Spin Squeezing in the Ising Model

Cited by in corpus (9)

• Constraints on the uncertainties of entangled symmetric qubits
• Spin squeezing in symmetric multiqubit states with two distinct Majorana spinors
• Spin squeezing in Dicke-class of states with non-orthogonal spinors
• SU(2) Invariants of Symmetric Qubit States
• Local sum uncertainty relations for angular momentum operators of bipartite permutation symmetric systems
• Sum Uncertainty Relations: Uncertainty Regions for Qubits and Qutrits
• Loss of exchange symmetry in multiqubit states under Ising chain evolution
• Spin geometry of entangled qubits under bilocal decoherence modes
• Lorentz invariants of pure three-qubit states