Classification and quantification of multipartite entanglement for arbitrary quantum states

Classify and quantify multipartite entanglement for arbitrary quantum states by developing general, scalable methods that distinguish entanglement types and provide robust measures across systems with more than two subsystems.

Background

Multipartite entanglement is substantially richer and more complex than bipartite entanglement. The authors explicitly cite its classification and quantification for arbitrary states as an unresolved problem, reflecting the lack of universally accepted frameworks to capture its many inequivalent forms.

Resolving this problem would provide foundational tools needed to compare and utilize entanglement in complex quantum systems, with implications for quantum computation, communication, and many-body physics.

References

In spite of continuous progress, the current state of entanglement theory is still marked by a number of outstanding unresolved problems. These problems range from the complete classification of mixed-state bipartite entanglement to entanglement in systems with continuous degrees of freedom, and the classification and quantification of multipartite entanglement for arbitrary quantum states.

— Epistemic vs Ontic Classification of quantum entangled states?  (1206.2916 - Caponigro et al., 2012) in Section 'Systems and Partitions', opening paragraph