Non-Fermi Liquid Behaviors in the Hubbard model on the Honeycomb lattice

Abstract

In this paper we study the low temperature ($T\rightarrow 0$) behaviors of the weakly interacting Hubbard model on the honeycomb lattice with a bare chemical potential, which takes values in a small neighborhood of the renormalized chemical potential $\mu$, which is fixed to be $1$. We prove that the two-point Schwinger's function is an analytic function of the coupling constant $\lambda$ in the domain $|\lambda|\cdot|\log T|^2<1$. But the ground state of this model is not a Fermi liquid, because analytic properties of self-energy don't satisfy the Salmhofer's criterion on the Fermi liquids at finite temperature.