Stability of Insulating Phases in the Hubbard Model: a Cluster Expansion

Details Stability of Insulating Phases in the Hubbard Model: a Cluster Expansion Stability of Insulating Phases in the Hubbard Model: a Cluster Expansion

1993-10-14

arxiv.org/abs/cond-mat/9310031v1

Physics

Condensed Matter

18 pages, Plain-TeX, TKM 08/93

Scientific paper

The stability of the insulating regime of the Hubbard model on a $d$-dimensional lattice, which is characterized by an exponential decay of the Green's functions, is investigated in terms of a cluster expansion. This expansion for the Green's function is organized in terms of connected clustered transfer matrices. An upper bound for the expansion terms is derived for the hopping rate ${\bar t}$ depending on the coupling constant $U$ as ${\bar t}