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arXiv · 2508.20184

$su(2)$ symmetry of XX spin chains

Nicolas Crampé·Rafael I. Nepomechie·Luc Vinet·Nabi Zare Harofteh
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Abstract

We show that, after suitably adjusting a uniform transverse magnetic field, the generic inhomogeneous open XX spin chain has a two-fold degeneracy, and an exact $su(2)$ symmetry whose "inhomogeneous" nonlocal generators depend on coefficients that can be explicitly computed for models associated with discrete orthogonal polynomials.

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Nicolas Crampé, Rafael I. Nepomechie, Luc Vinet, Nabi Zare Harofteh. 2025-12-09. $su(2)$ symmetry of XX spin chains. https://doi.org/10.1007/s11040-025-09544-w

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