$su(2)$ symmetry of XX spin chains
Nicolas Crampé, Rafael I. Nepomechie, Luc Vinet, Nabi Zare Harofteh
公開日: 2025/8/27
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.