https://doi.org/10.1140/epjd/s10053-026-01182-3
Research - Photon
Entanglement measures for multipartite quantum systems: limitations and new approaches
Department of Physics, Faculty of Science, Shahid Chamran University of Ahvaz, Ahvaz, Iran
a
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Received:
5
November
2025
Accepted:
7
May
2026
Published online:
26
May
2026
Abstract
In this research, we investigate the distribution of entanglement within two entangled n-qubit systems using the one-tangle and π-tangle. Our analysis reveals that for certain quantum states such as the generalized W state, where the probability coefficients depend on the number of qubits, increasing the system size causes these traditional measures to gradually diminish, with the monogamy relation tending toward equality. This behavior highlights a limitation of conventional tangle-based measures in capturing multipartite correlations in large systems. To overcome this, we introduce two alternative measures: the sum of squared one-tangles and the generalized residual entanglement. Unlike the standard one-tangle and π-tangle, these new quantities remain robust as the number of qubits increases. Moreover, we propose a strong monogamy relation that preserves nontrivial entanglement distribution even in the large-n limit. Our results provide a refined framework for quantifying entanglement in high-dimensional multipartite systems.
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© The Author(s), under exclusive licence to EDP Sciences, SIF and Springer-Verlag GmbH Germany, part of Springer Nature 2026
Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
