Speaker: Szilárd Szalay (Wigner RCP)
Title: Multipartite entanglement and correlation
Date: Tuesday, March 4, 2025. 10:00
Place: Building 1, Conference room
Abstract:
Entanglement is the most remarkable manifestation of the nonclassical behaviour of quantum systems, still puzzling the community for almost a hundred years. A bipartite quantum system can either be separable or entangled, while in the multipartite case entanglement has a rich structure with many exciting features. In this talk, after recalling some basics of entanglement theory, we outline some of our main contributions to the field as follows. The natural generalisation of the separable/entangled dichotomy to multipartite systems is the partial separability classification, which we worked out for arbitrary number of discrete finite subsystems, resulting in a nice three-level building of order-theoretical constructions. Permutation invariant multipartite entanglement properties represent an important special case, among which the one-parameter families, e.g., k-producibility or k-partitionability, are even more important even more special cases. We formulate observable-independent entropic entanglement measures for all the multipartite entanglement properties, and also entanglement-depth like quantities for the one-parameter families, the convex version of which lead to strong metrological multipartite entanglement criteria.
