Ferromagnetism in d-Dimensional SU(n) Hubbard Models with Nearly Flat Bands

摘要: We present rigorous results for the SU(n) Fermi–Hubbard models with finite-range hopping in d ( $$\ge 2$$ ) dimensions. The are defined on a class of decorated lattices. first study flat bands at bottom single-particle spectrum and prove that ground states exhibit ferromagnetism when number particles is equal to unit cells. then perturb by adding particular terms make dispersive. Under same filling condition, it proved remain ferromagnetic sufficiently Coulomb repulsion large.