Dynamical Mean-Field Theory for Doped Antiferromagnets

TL;DR

This paper extends dynamical mean-field theory to analyze doped antiferromagnets, capturing the transition from antiferromagnetic to short-range order and matching well with numerical data.

Contribution

It introduces a generalized DMFT approach that incorporates spin fluctuations to study doping effects in the Hubbard model.

Findings

Spectral properties agree with quantum Monte Carlo and exact diagonalization.

Finite doping spectra show a Mott-Hubbard gap and a pseudogap.

The theory accurately models the crossover from antiferromagnetic to short-range order.

Abstract

We have generalized the dynamical mean-field theory to study the doping dependence of the crossover from antiferromagnetic to short-range order modelled by an incommensurate spin density wave in the Hubbard model. The local selfenergy which includes spin fluctuations gives quasiparticle weights and spectral properties in good agreement with quantum Monte Carlo and exact diagonalization data in two dimensions. The spectra at finite doping are characterized by a Mott-Hubbard `gap' accompanied by a pseudogap induced by the local spin order.