Equivalence and solution of anisotropic spin-1 models and generalized t-J fermion models in one dimension

The authors study the relationship of two 'q-deformed' spin-1 chains-both of them are solvable models-with a generalized supersymmetric t-J fermion model in one dimension. One of the spin-1 chains is an anisotropic VBS model for which they calculate ground state and ground-state properties. The other spin-1 chain corresponds to the Zamolodchikov-Fateev model which is solvable by Bethe ansatz and is equivalent to a certain t-J model. The two spin-1 models intersect for a certain value of the 'deformation' parameter q in a second-order phase transition.