Berlin 2024 – scientific programme

Parts | Days | Selection | Search | Updates | Downloads | Help

QI: Fachverband Quanteninformation

QI 5: Entanglement Theory

QI 5.1: Invited Talk

Monday, March 18, 2024, 15:00–15:30, HFT-FT 101

Multi-copy activation of genuine multipartite entanglement in continuous-variable systems — Klára Baksová¹, Olga Leskovjanová², Ladislav Mišta², •Elizabeth Agudelo¹, and Nicolai Friis¹ — ¹Atominstitut, Technische Universität Wien, Stadionallee 2, 1020 Vienna, Austria — ²Department of Optics, Palacký University, 17. Listopadu 12, 771~46 Olomouc, Czech Republic

In multipartite systems, entanglement takes various forms. Some mixed states show entanglement across every possible cut of a multipartite system, though they originate from separable states in different partitions. Genuine multipartite entangled (GME) states, not formed by mixing partition-separable states, are intriguing. Advances in quantum tech raise questions about this framework when multiple state copies are accessible. States in finite dimensions are GME-activatable if they are not partially separable across any one bipartition, likely true for infinite dimensions too. We explore this in the continuous-variable context, providing GME-activatable non-Gaussian state examples. For Gaussian states, using a biseparability criterion for the covariance matrix, we find it fails to detect GME activation. We find fully inseparable Gaussian states that meet this criterion but can still be GME, showing the criterion's insufficiency for Gaussian states. To the best of our knowledge, there is no documented instance of a Gaussian state that is both fully inseparable and definitively biseparable, highlighting a gap in our current understanding of these particular quantum systems.

Keywords: genuine multipartite entanglement; continuous-variable entanglement; Multi-copy entanglement properties