Higher Order Matrix SUSY Transformations in Two-Dimensional Quantum   Mechanics
  The iteration procedure of supersymmetric transformations for the two-dimensional Schroedinger operator is implemented by means of the matrix form of factorization in terms of matrix 2x2 supercharges. Two different types of iterations are investigated in detail. The particular case of diagonal initial Hamiltonian is considered, and the existence of solutions is demonstrated. Explicit examples illustrate the construction. 
F. Cannata, M.V. Ioffe, A.I.Neelov, D.N. Nishnianidze