Antiferromagnetic fluctuations in the one-dimensional Hubbard model

Abstract

We study the low-temperature critical behavior of the one-dimensional Hubbard model near half filling caused by enhanced antiferromagnetic fluctuations. We use a mean-field-type approximation with a two-particle self-consistency renormalizing the bare interaction. It allows us to control a transition from high to low temperatures as well as from weak to strong-coupling. We show that there is a crossover temperature $T_0=t\exp \{-1/U\rho (0)\}$ for arbitrary interaction $U>0$ and the bare density of states at the Fermi energy $\rho (0)>0$. The solution at lower temperatures goes over to strong coupling and approaches a quantum critical point with the diverging staggered susceptibility and a gap in the excitation spectrum at zero temperature.

6 pages, 2 figures, Contributed talk at MMM 2020, to appear in AIP Advances