Analyticity in Hubbard models
arXiv:cond-mat/9810320 · doi:10.1023/A:1004599410952
Abstract
The Hubbard model describes a lattice system of quantum particles with local (on-site) interactions. Its free energy is analytic when βt is small, or βt^2/U is small; here, βis the inverse temperature, U the on-site repulsion and t the hopping coefficient. For more general models with Hamiltonian H = V + T where V involves local terms only, the free energy is analytic when β||T|| is small, irrespectively of V. The Gibbs state exists in the thermodynamic limit, is exponentially clustering and thermodynamically stable. These properties are rigorously established in this paper.
16 pages, LaTeX 2e, 7 figures. To appear in J. Stat. Phys. 95 (May 1999)