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arXiv · 2411.15032

Threetangle in the XY-model class with a non-integrable field background

Jörg Neveling·Andreas Osterloh
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Abstract

The square root of the threetangle is calculated for the transverse XY-model with an integrability-breaking in-plane field component. To be in a regime of quasi-solvability of the convex roof, here we concentrate here on a 4-site model Hamiltonian. In general, the field and hence a mixing of the odd/even sectors, has a detrimental effect on the threetangle, as expected. Only in a particular spot of models with no or weak inhomogeneity $γ$ does a finite value of the tangle prevail in a broad maximum region of the field strength $h\approx 0.3\pm 0.1$. There, the threetangle is basically independent of the non-zero angle $α$. This system could be experimentally used as a quasi-pure source of threetangled states or as an entanglement triggered switch depending on the experimental error in the field orientation.

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Jörg Neveling, Andreas Osterloh. 2025-01-16. Threetangle in the XY-model class with a non-integrable field background. https://doi.org/10.1103/qtg3-z3yh

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