2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/54592I study the technique of Algebraic Bethe Ansatz for solving integrable models and show how it works in detail on the simplest example of spin 1/2 XXX magnetic chain. Several other models are treated more superficially, only the specific details are given. Several parameters, appearing in these generalizations: spin $s$, anisotropy parameter $\ga$, shift $\om$ in the alternating chain, allow to include in our treatment most known examples of soliton theory, including relativistic model of Quantum Field Theory.Les-Houches lectures, 59 pages, LatexHigh Energy Physics - Theorytext