arXiv:cond-mat/9710256 · Physical Review Letters
Strong-Coupling Expansion for the Hubbard Model
Stéphane Pairault, David Sénéchal, A.–M. S. Tremblay
Abstract
A strong-coupling expansion for models of correlated electrons in any dimension is presented. The method is applied to the Hubbard model in $d$ dimensions and compared with numerical results in $d\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}1$. Third order expansion of the Green's function suffices to exhibit both the Mott metal-insulator transition and a low-temperature regime where antiferromagnetic correlations are strong. It is predicted that some of the weak photoemission signals observed in one-dimensional systems such as ${\mathrm{SrCuO}}_{2}$ should become stronger as temperature increases away from the spin-charge separated state.