Polarization squeezing and multipartite entanglement of triphoton states

TL;DR

This paper develops an analytical framework based on angular momentum theory to study polarization squeezing and multipartite entanglement in triphoton states, linking entanglement with polarization properties and quantum Fisher information.

Contribution

It introduces a new analytical approach to analyze polarization squeezing and entanglement in triphoton states, connecting these phenomena with quantum Fisher information.

Findings

Maximally entangled NOON states cause a flip in mean polarization.

Analytical expressions for mean polarization and variances of Stokes parameters.

Entanglement correlates with polarization properties and quantum Fisher information.

Abstract

Based upon standard angular momentum theory, we develop a framework to investigate polarization squeezing and multipartite entanglement of a quantum light field. Both mean polarization and variances of the Stokes parameters are obtained analytically, with which we study recent observation of triphoton states [L. K. Shalm {\it et al}, Nature \textbf{457}, 67 (2009)]. Our results show that the appearance of maximally entangled NOON states accompanies with a flip of mean polarization and can be well understood in terms of quantum Fisher information.