INTEGRABLE EXTENSIONS OF HUBBARD HAMILTONIAN

We construct the family of spin-chain Hamiltonians, which have affine quantum group symmetry U-q (g) over cap. Their eigenvalues coincide wi th the eigenvalues of the usual spin-chain Hamiltonians, but have the degeneracy of levels, corresponding to affine U-q (g) over cap. The sp ace of states of these spin-chains is formed by the tensor product of fully reducible representations. The fermionic representations of spin -chain Hamiltonians, which have affine quantum group symmerty, was con sructed. They correspond to new extensions of Hubbard Hamiltonians. Th e exact ground state of some examples is presented, exhibiting superco nducting behavior via eta-pairing mechanism.