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The ground state entanglement in the $XXZ$ model

Shi-Jian Gu·Guang-Shan Tian·Hai-Qing Lin
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Abstract

In this paper, we investigate spin entanglement in the $XXZ$ model defined on a $d$-dimensional bipartite lattice. The concurrence, a measure of the entanglement between two spins, is analyzed. We prove rigorously that the ground state concurrence reaches maximum at the isotropic point. For dimensionality $d \ge 2$, the concurrence develops a cusp at the isotropic point and we attribute it to the existence of magnetic long-range order.

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Shi-Jian Gu, Guang-Shan Tian, Hai-Qing Lin. 2004-08-16. The ground state entanglement in the $XXZ$ model. https://doi.org/10.1103/physreva.71.052322

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