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arXiv · 2609.07380

Multi-copy and Catalytic Superactivation of Genuine Multipartite Nonlocality

Bora Ulu·Mirjam Weilenmann·Nicolas Brunner
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Abstract

Genuine multipartite Bell nonlocality (GMNL) aims at capturing correlations between many distant observers that are globally Bell nonlocal. A commonly used definition for GMNL is based on biseparable models constructed from non-signalling correlations. Here we uncover an effect of superactivation of GMNL in this framework. Specifically, by locally wiring together two copies of a biseparable correlation, i.e. not GMNL, one can obtain another correlation that is GMNL. We show that this is possible for any number of parties, and for quantum-realizable correlations. Finally, we show that superactivation of GMNL is also possible at the single-copy level, via a catalytic protocol involving only local wirings. These results question the operational meaning of this definition of GMNL.

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Bora Ulu, Mirjam Weilenmann, Nicolas Brunner. 2026-09-07. Multi-copy and Catalytic Superactivation of Genuine Multipartite Nonlocality. https://arxiv.org/abs/2609.07380

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