Su(3) Algebraic Structure of the Cuprate Superconductors Model based on   the Analogy with Atomic Nuclei
  A cuprate superconductor model based on the analogy with atomic nuclei was shown by Iachello to have an $su(3)$ structure. The mean-field approximation Hamiltonian can be written as a linear function of the generators of $su(3)$ algebra. Using algebraic method, we derive the eigenvalues of the reduced Hamiltonian beyond the subalgebras $u(1)\bigotimes u(2)$ and $so(3)$ of $su(3)$ algebra. In particular, by considering the coherence between s- and d-wave pairs as perturbation, the effects of coherent term upon the energy spectrum are investigated. 
Shuo Jin, Bing-Hao Xie, Feng Pan, Joseph L. Birman, and Mo-Lin Ge