We construct a factorizing Drinfel'd twist for a face type model equivalent to the XY Z model.Completely symmetric expressions for the operators of the monodromy matrix are obtained
We study representation theory of Drinfel'd twists, in terms of what we call F matrices, associated to finite dimensional irreducible modules of quantum affine algebras, and which factorize the corresponding (unitary) R matrices. We construct explicitly such factorizing F matrices for irreducible tensor products of the fundamental representations of the quantum affine algebra sl2 and its associated Yangian. We then apply these constructions to the XXX and XXZ quantum spins chains of finite length in the framework of the Algebraic Bethe Ansatz.
We construct Drinfel'd twists for the rational sl ( n ) XXX model giving rise to a completely symmetric representation of the monodromy matrix. We obtain a polarization-free representation of the pseudoparticle creation operators figuring in the construction of the Bethe vectors within the framework of the quantum inverse scattering method. This representation enables us to resolve the hierarchy of the nested Bethe ansatz for the sl ( n ) invariant rational Heisenberg model. Our results generalize the findings of Maillet and Sanchez de Santos for sl (2) models.