Full multipartite entanglement of frequency comb Gaussian states

TL;DR

This paper analyzes multipartite entanglement in Gaussian states generated by femtosecond frequency combs, introducing new criteria and verifying full entanglement across numerous partitions in experimental states.

Contribution

It develops a novel method for detecting multipartite entanglement in frequency comb Gaussian states, extending beyond bipartitions and optimizing entanglement verification.

Findings

Full entanglement certified in 4-, 6-, and 10-mode states.

Maximal significance achieved through numerical optimization.

Entanglement verified across thousands of partitions.

Abstract

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 115974 possible nontrivial partitions, respectively.