Absence of a Slater Transition in The Two-Dimensional Hubbard Model

Abstract

We present well-controlled results on the metal to insulator transition (MIT) within the paramagnetic solution of the dynamical cluster approximation (DCA) in the two-dimensional Hubbard model at half-filling. In the strong coupling regime, a local picture describes the properties of the model; there is a large charge gap $\Delta \approx U$. In the weak-coupling regime, we find a symbiosis of short-range antiferromagnetic correlations and moment formation cause a gap to open at finite temperature as in one dimension. Hence, this excludes the mechanism of the MIT proposed by Slater long ago.