On Integrable Quantum Group Invariant Antiferromagnets

Abstract

A new open spin chain hamiltonian is introduced. It is both integrable (Sklyanin`s type $K$ matrices are used to achieve this) and invariant under ${\mathcal{U}}_{\hat{I}}\mu (sl(2))$ transformations in nilpotent irreps for $\hat{I}{\mu }^3=1$. Some considerations on the centralizer of nilpotent representations and its representation theory are also presented.

IFF-5/92, 13 pages, LaTex file, 8 figures available from authors