New Two-Dimensional Integrable Quantum Models from SUSY Intertwining
  Supersymmetrical intertwining relations of second order in the derivatives are investigated for the case of supercharges with deformed hyperbolic metric $g_{ik}=diag(1,-a^2)$. Several classes of particular solutions of these relations are found. The corresponding Hamiltonians do not allow the conventional separation of variables, but they commute with symmetry operators of fourth order in momenta. For some of these models the specific SUSY procedure of separation of variables is applied. 
M.V.Ioffe, J.Negro, L.M.Nieto, D.N.Nishnianidze