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arXiv · 2007.03786

Quantification and observation of genuine three-party coherence: A solution based on classical optics

X. -F. Qian·S. A. Wadood·A. N. Vamivakas·J. H. Eberly
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Abstract

We introduce a quantification of genuine three-party pure-state coherence for wave fields, classical and quantum, by borrowing concepts from classical optics. The tensor structure of a classical paraxial light beam composed of three principle degrees of freedom is shown to be equivalent to that of a three-qubit quantum state. The traditional basis-independent optical coherence quantity called degree of polarization is then determined to be the desired quantitative two-party coherence measure. When appropriately generalized, a set of fundamental constraint relations is derived among three two-party coherences. The constraint relations can be geometrically interpreted and visualized as tetrahedra nested within a coherence cube. A measure of three-party coherence is defined based on the constraints. We are reporting completed experimental tests and confirmations of the constraints as well as measurement of three-party coherence in the optical context. Our approach based on classical optics also opens an alternative way to analyze quantum coherence.

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X. -F. Qian, S. A. Wadood, A. N. Vamivakas, J. H. Eberly. 2020-12-24. Quantification and observation of genuine three-party coherence: A solution based on classical optics. https://doi.org/10.1103/physreva.102.062424

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