The typicality of symmetry-induced entanglement
- URL: http://arxiv.org/abs/2603.20786v1
- Date: Sat, 21 Mar 2026 12:24:08 GMT
- Title: The typicality of symmetry-induced entanglement
- Abstract summary: We show that most symmetric and separable states are actually far from being symmetrically separable.<n>We discuss some consequences of our results for quantum tasks in the presence of a superselection rule or in the absence of a common reference frame.
- Score: 0.0
- License: http://creativecommons.org/licenses/by/4.0/
- Abstract: In the presence of a globally conserved charge $N$, a natural question is whether a given separable state can be separated into charge-conserving components. We dub this problem the Symmetric Separability Problem (SSP). On random states, the SSP is answered negatively with probability one for almost all $N$. Using a witness to the failure of symmetric separability, namely the number entanglement (NE) introduced in arXiv:2110.09388, we show that most symmetric and separable states are actually far from being symmetrically separable, with the NE featuring Gaussian concentration around a strictly positive mean value. We discuss some consequences of our results for quantum tasks in the presence of a superselection rule or in the absence of a common reference frame. Progress is made on the question of the size of the separable space constrained by $N$. We also touch upon the question of the complexity of SSP, and multiparty entanglement.
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