On the flux phase conjecture at half-filling: an improved proof
arXiv:cond-mat/9604043 · doi:10.1007/BF02199361
Abstract
We present a simplification of Lieb's proof of the flux phase conjecture for interacting fermion systems -- such as the Hubbard model --, at half filling on a general class of graphs. The main ingredient is a procedure which transforms a class of fermionic Hamiltonians into reflection positive form. The method can also be applied to other problems, which we briefly illustrate with two examples concerning the $t-V$ model and an extended Falicov-Kimball model.
23 pages, Latex, uses epsf.sty to include 3 eps figures, to appear in J. Stat. Phys., Dec. 1996