  We construct the family of spin chain Hamiltonians, which have affine quantum
group symmetry. Their eigenvalues coincide with the eigenvalues of the usual
spin chain Hamiltonians, but have the degeneracy of levels, corresponding to
affine quantum group. The space of states of these spin chains is formed by the
tensor product of fully reducible representations of quantum group. The
fermionic representations of constructed spin chain Hamiltonians show that we
have new extensions of Hubbard Hamiltonians. All of them are integrable and
have affine quantum group symmetry. The exact ground state of a such type model
is presented, exhibiting superconducting behavior via eta-pairing mechanism.
