Detecting multiparticle entanglement of Dicke states

Area of Science:

• Quantum physics
• Atomic physics
• Quantum information science

Background:

• Recent experiments have successfully produced thousands of neutral atoms entangled in their spin degrees of freedom.
• Quantifying entanglement in many-particle systems is crucial for advancing quantum technologies.

Purpose of the Study:

• To present a novel criterion for estimating entanglement based on global spin measurements.
• To demonstrate the criterion's superiority over existing methods and its applicability to diverse entangled states, including Dicke states.

Main Methods:

• Development of a new entanglement criterion utilizing global spin measurements.
• Experimental generation of a Dicke-like spin-correlated state in a Bose-Einstein condensate.
• Application of the criterion to experimentally produced states.

Main Results:

• The new criterion outperforms previous methods in estimating entanglement.
• The criterion is applicable to a broader range of entangled states, such as Dicke states.
• Experimental verification confirmed at least genuine 28-particle entanglement in the produced Bose-Einstein condensate state.
• A generalized squeezing parameter of -11.4(5) dB was inferred.

Conclusions:

• The developed criterion provides a robust and versatile tool for quantifying multi-particle entanglement.
• The experimental demonstration validates the criterion's effectiveness and highlights advancements in creating and characterizing complex entangled states.
• This work contributes to the fundamental understanding of quantum entanglement and its potential applications in quantum computing and sensing.