Characterization of multipartite entanglement for one photon shared among four optical modes.

Multipartite entanglement for one photon among four optical modes

Direct generation of spatial quadripartite continuous variable entanglement in an optical parametric oscillator.

Multipartite entanglement is used for quantum information applications, such as building multipartite quantum communications. Generally, generation of multipartite entanglement is based on a complex beam-splitter network. Here, based on the spatial freedom of light, we experimentally demonstrated spatial quadripartite continuous variable entanglement among first-order Hermite-Gaussian modes usi...

06 08 05 5 v 2 2 1 Fe b 20 07 Demonstrating multipartite entanglement of single - particle W states : linear optical schemes

We present two linear optical schemes using nonideal photodetectors to demonstrate inseparability of W -type N-partite entangled states containing only a single photon. First, we show that the pairwise entanglement of arbitrary two modes chosen from N optical modes can be detected using the method proposed by Nha and Kim [Phys. Rev. A 74, 012317 (2006)], thereby suggesting the full inseparabili...

Bipartite and Multipartite Entanglement of Gaussian States

In this chapter we review the characterization of entanglement in Gaus-sian states of continuous variable systems. For two-mode Gaussian states, we discuss how their bipartite entanglement can be accurately quantified in terms of the global and local amounts of mixedness, and efficiently estimated by direct measurements of the associated purities. For multimode Gaussian states endowed with loca...

Multipartite continuous-variable entanglement from concurrent nonlinearities

We show theoretically that concurrent interactions in a second-order nonlinear medium placed inside an optical resonator can generate multipartite entanglement between the resonator modes. We show that there is a mathematical connection between this system and van Loock and Braunstein’s proposal for entangling N continuous quantum optical variables by interfering with the outputs of N degenerat...