From Slater to Mott-Heisenberg physics: The antiferromagnetic phase of the Hubbard model

TL;DR

This paper investigates the optical conductivity of the half-filled Hubbard model in the antiferromagnetic state at zero temperature, revealing a smooth crossover from Slater to Mott-Heisenberg physics without a sharp transition.

Contribution

It provides a detailed analysis of the antiferromagnetic phase of the Hubbard model using dynamical mean-field theory, highlighting the continuous evolution between weak and strong coupling regimes.

Findings

Identification of Slater insulator signatures at weak coupling

Description of Mott-Heisenberg physics at strong coupling

Absence of a sharp transition, only a smooth crossover

Abstract

We study the optical conductivity of the one-band Hubbard model in the N\'eel state at half filling at T=0 using the dynamical mean-field theory. For small values of the Coulomb parameter clear signatures of a Slater insulator expected from a weak-coupling theory are found, while the strongly correlated system can be well described in terms of a Mott-Heisenberg picture. However, in contrast to the paramagnet, we do not find any evidence for a transition between these two limiting cases but rather a smooth crossover as a function of the Coulomb interaction.