Theory of Ferrimagnetism in the Hubbard Model on Bipartite Lattices with   Spectrum Symmetry
  In this paper we developed theory of the ferrimagnetism in the Hubbard model on bipartite lattices with spectrum symmetry. We then study the defect-induced ferrimagnetic orders in three models and explored the universal features. 
Yang Xue, Jing He, Xing-Hai Zhang and Su-Peng Kou
cond-mat.str-el cond-mat.mes-hall