Abstract From Zou and Anderson's spinon-bolon effective Hamiltonian, for very large Coulomb repulsion U, we consider the problem of ferromagnetism on the square lattice by studying the fluctuation effect of bosons (holons).
LI DING-GUO,ZHENG RUI-LIN,HU LIAN. INVESTIGATION ON FERROMAGNETIC PHASE IN THE 2-DIMENSION LARGE-U HUBBARD MODEL. Acta Phys. Sin., 1992, 41(2): 323-328.