Can multipartite entanglement be characterized by two-point connected correlation functions?

Journal article

We discuss under which conditions multipartite entanglement in mixed quantum states can be characterized only in terms of two-point connected correlation functions, as it is the case for pure states. In turn, the latter correlations are defined via a suitable combination of (disconnected) one- and two-point correlation functions. In contrast to the case of pure states, conditions to be satisfied turn out to be rather severe. However, we were able to identify some interesting cases, as when the point-independence is valid of the one-point correlations in each possible decomposition of the density matrix, or when the operators that enter in the correlations are (semi-)positive/negative defined

Authors: Lepori, L; Trombettoni, A; Giuliano, D; Kombe, J; Malo, JY

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: IOP Publishing
• Journal: Journal of Physics A: Mathematical and Theoretical
• Volume: 56
• Issue: 30
• Pages: 305302-305302
• Publication date: 2023-06-09
• DOI: 10.1088/1751-8121/acdd36
• EISSN: 1751-8121
• ISSN: 1751-8113
• Language: English
• Keywords: Spectral density; Pure mathematics; Statistics; Quantum correlation; Squashed entanglement; Physics; Point (geometry); Quantum mechanics; Correlation; Quantum; Multipartite; Statistical physics; Mathematics; Quantum discord; Independence (probability theory); Quantum entanglement; Multipartite entanglement; Correlation function (quantum field theory)