Quantum group deformation of the Kittel–Shore model
Ángel Ballesteros, Iván Gutiérrez-Sagredo, Víctor Mariscal +1 more
Abstract The Kittel–Shore (KS) Hamiltonian describes N spins with long-range interactions that are identically coupled; therefore, this (mean-field) model is also known as the Heisenberg XXX model on the complete graph. In this paper, the underlying U ( su ( 2 ) ) coalgebra symmetry of the KS model is demonstrated for arbitrary spins, and the quantum deformation of the KS Hamiltonian ( q -KS model) is obtained using the corresponding U q ( su ( 2 ) ) quantum group. By construction, the existence of such a symmetry guarantees that all integrability properties of the KS model are preserved under q -deformation. In particular, the q -KS model for spin- 1 / 2 particles is analysed, the cases with N = 2 and 3 spins are studied in detail, and higher-spin q -KS models are sketched. As a first excursion into the thermodynamic properties of the spin- 1 / 2 q -KS model, the dependence of the Curie temperature on the deformation parameter is studied through numerical analysis.
arXiv:2502.20884•Journal of Physics A Mathematical and Theoretical•Oct 13, 2025•3 citations