Static vs. dynamical mean field theory of Mott antiferromagnets

Abstract

Studying the antiferromagnetic phase of the Hubbard model by dynamical mean field theory, we observe striking differences with static (Hartree-Fock) mean field: The Slater band is strongly renormalized and spectral weight is transferred to spin-polaron side bands. Already for intermediate values of the interaction $U$ the overall bandwidth is larger than in Hartree-Fock, and the gap is considerably smaller. Such differences survive any renormalization of $U$. Our photoemission experiments for Cr-doped V${}_2$O${}_3$ show spectra qualitatively well described by dynamical mean field theory.

6 pages, 5 figures - one figure added and further details about quasiparticle dispersion