Superconductivity and Instabilities in the t-t' Hubbard Model
  We present a stability analysis of the 2D t-t' Hubbard model on a square lattice for t' = -t/6. We find possible phases of the model (d-wave Pomeranchuk and superconducting states, band splitting, singlet and triplet flux phases), and study the interplay of them. 
F. Wegner and V. Hankevych