On rational R-matrices with adjoint SU(n) symmetry
  Using the representation theory of Yangians we construct the rational R-matrix which takes values in the adjoint representation of SU(n). From this we derive an integrable SU(n) spin chain with lattice spins transforming under the adjoint representation. However, the resulting Hamiltonian is found to be non-Hermitian. 
Laurens Stronks, Johan van de Leur and Dirk Schuricht
math-ph cond-mat.str-el hep-th math.MP