Multi-partite entanglement detection with non symmetric probing

Abstract

We show that spin squeezing criteria commonly used for entanglement detection can be erroneous, if the probe is not symmetric. We then derive a lower bound on squeezing for separable states in spin systems probed asymmetrically. Using this we further develop a procedure that allows us to verify the degree of entanglement of a quantum state in the spin system. Finally, we apply our method for entanglement verification to existing experimental data, and use it to prove the existence of tri-partite entanglement in a spin squeezed atomic ensemble.

7 pages, 2 figures (Include Supplemental material)

References in corpus (11)

• Entanglement detection
• Squeezing and entanglement in a Bose-Einstein condensate
• Dissipative Phase Transition in Central Spin Systems
• Deterministic Squeezed States with Joint Measurements and Feedback
• Non-Destructive Probing of Rabi Oscillations on the Cesium Clock Transition near the Standard Quantum Limit
• Spin squeezing in an ensemble of quadrupolar nuclei NMR system
• Probability density function characterization of multipartite entanglement
• Spin squeezing of atomic ensembles by multi-colour quantum non-demolition measurements
• Entanglement and Extreme Spin Squeezing for a Fluctuating Number of Indistinguishable Particles
• Entangled collective-spin states of atomic ensembles under non-uniform atom-light interaction
• Inhomogeneous Light Shift Effects on Atomic Quantum State Evolution in Non-Destructive Measurements

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• Measure of tripartite quantum correlation in multiqubit symmetric pure state