Using the linked-cluster expansion method, we have calculated the uniform and the staggered susceptibility of a single-band Hubbard model. We make correction of previous results of Kubo and Zhao et al.
Using the linked-cluster expansion, we have obtained the free energy, uniform susceptibility, and staggered susceptibility of the s-band Hubbard model to the sixth order in terms of βt, where t is the hopping integral to the nearest neighbors and β is the inverse of temperature. We show that a special technique based on the multiple-site Wick reduction theorem is more convenient than previous perturbation calculations. Our linked-cluster expansion result is for an arbitrary value of the on-site repulsion U. It has made corrections of previous results of several papers (up to fourth order) and achieved the sixth-order term.
Using the fourth-order perturbation expansion, we have calculated the uniform and the staggered magnetic susceptibility of the s-band Hubbard model. The Curie and the N\'eel temperatures are derived and the magnetic phase diagrams are constructed. Our calculation improves on the earlier work of Kubo.