Jiang Tao, Liu Jinming. Ferromagnetism in the 3 Dimensional Hubbard Hirsch Model[J]. Acta Scientiarum Naturalium Universitatis SunYatseni, 1996,35(6):46-49.
Jiang Tao, Liu Jinming. Ferromagnetism in the 3 Dimensional Hubbard Hirsch Model[J]. Acta Scientiarum Naturalium Universitatis SunYatseni, 1996,35(6):46-49.DOI:
By using mean field theory and a perturbative canonical transformation
the ferromagnetism in the 3 dimensional Hubbard Hirsch model is investigated. It is shown that ferromagnetism only occurs when J ″>0 for small U or large U . For mediate value of U
the ferromagnetiam may or may not appear in the Hubbard model
and cannot be determined in the theory. The ferromagnetism regions are always smaller than that for half filling for a fixed J ″.