Root-of-unity Symmetry of the XXZ Spin Chain of Higher Spin1

We construct the fusion operators in the generalized τ -model using the fused L-operators, and verify the fusion relations with the truncation identity. The algebraic Bethe ansatz discussion is conducted on two special classes of τ (2) which include the superintegrable chiral Potts model. We then perform the parallel discussion on the XXZ spin chain at roots of unity, and demonstrate that the sl2-loop-algebra symmetry exists for the root-of-unity XXZ spin chain with a higher spin, where the evaluation parameters for the symmetry algebra are identified by the explicit Fabricius-McCoy current for the Bethe states. Parallels are also drawn to the comparison with the superintegrable chiral Potts model. 1999 PACS: 05.50.+q, 02.20.Tw, 75.10Jm 2000 MSC: 17B65, 39B72, 82B23