Verifying multipartite mode entanglement of W states

Pavel Lougovski, S J van Enk, Kyung Soo Choi, Scott B Papp, Hui Deng, H J Kimble
2009 New Journal of Physics  
We construct a method for verifying mode entanglement of N-mode W states. The ideal W state contains exactly one excitation symmetrically shared between N modes, but our method takes the existence of higher numbers of excitations into account, as well as the vacuum state and other deviations from the ideal state. Moreover, our method distinguishes between full N-party entanglement and states with M-party entanglement with M<N, including mixtures of the latter. We specialize to the case N=4 for
more » ... llustrative purposes. In the optical case, where excitations are photons, our method can be implemented using linear optics.
doi:10.1088/1367-2630/11/6/063029 fatcat:dserfbsxjvedrnuuu5zrzt6rhi