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arXiv · 2312.16570

Multi-copy activation of genuine multipartite entanglement in continuous-variable systems

Klára Baksová·Olga Leskovjanová·Ladislav Mišta Jr.·Elizabeth Agudelo·Nicolai Friis
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Abstract

Multi-copy activation of genuine multipartite entanglement (GME) is a phenomenon whereby multiple copies of biseparable but fully inseparable states can exhibit GME. This was shown to be generically possible in finite dimensions. Here, we extend this analysis to infinite dimensions. We provide examples of GME-activatable non-Gaussian states. For Gaussian states, we apply a necessary biseparability criterion for the covariance matrix and show that it cannot detect GME activation. We further identify fully inseparable Gaussian states that satisfy the criterion but show that multiple and, in some cases, even single copies are GME. Thus, we show that the covariance-matrix biseparability criterion is not sufficient even for Gaussian states.

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Klára Baksová, Olga Leskovjanová, Ladislav Mišta Jr., Elizabeth Agudelo, Nicolai Friis. 2023-12-27. Multi-copy activation of genuine multipartite entanglement in continuous-variable systems. https://doi.org/10.22331/q-2025-04-09-1699

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