Analyticity in Hubbard Models
Abstract
The Hubbard model describes a lattice system of quantum particles with local (onsite) interactions. Its free energy is analytic when βt is small, or βt ^{2}/ U is small; here, β is the inverse temperature, U the onsite 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, irrespective of V. There exists a unique Gibbs state showing exponential decay of spatial correlations. These properties are rigorously established in this paper.
 Publication:

Journal of Statistical Physics
 Pub Date:
 May 1999
 DOI:
 10.1023/A:1004599410952
 arXiv:
 arXiv:condmat/9810320
 Bibcode:
 1999JSP....95..693U
 Keywords:

 Hubbard model;
 local interactions;
 analyticity of free energy;
 uniqueness of Gibbs states;
 Condensed Matter  Statistical Mechanics;
 Condensed Matter  Strongly Correlated Electrons
 EPrint:
 16 pages, LaTeX 2e, 7 figures. To appear in J. Stat. Phys. 95 (May 1999)