Full Multipartite Entanglement of Frequency-Comb Gaussian States
Stefan Gerke, Jan Sperling, W. Vogel, Yin Cai, Jonathan Roslund, Nicolas Treps, Claude Fabre · Physical Review Letters · 2015
An analysis is conducted of the multipartite entanglement for Gaussian states generated by the parametric down-conversion of a femtosecond frequency comb. Using a recently introduced method for constructing optimal entanglement criteria, a family of tests is formulated for mode decompositions that extends beyond the traditional bipartition analyses. A numerical optimization over this family is performed to achieve maximal significance of entanglement verification. For experimentally prepared 4-, 6-, and 10-mode states, full entanglement is certified for all of the 14, 202, and 115 974 possible nontrivial partitions, respectively.