Antiferromagnetism and metal insulator transition in the frustrated Hubbard model

Abstract

We present a review of recent results on properties of the antiferromagnetic phase of the Hubbard model obtained within the dynamical mean-field theory. The equations of the dynamical mean-field theory are solved with a suitably extended version of Wilson's numerical renormalization group. For the particle-hole symmetric model we present evidence that in the antiferromagnetic phase at half filling a crossover between a Slater type antiferromagnet to a Heisenberg antiferromagnet takes place. Away from half filling phase separation is found. Including magnetic frustration leads to the expected suppression of the antiferromagnet, but in contrast to previous expectations no distinct antiferromagnetic metal is found. Instead, a strong first-order transition between the paramagnetic metal and the antiferromagnetic insulator occurs.