Europhys. Lett.
Volume 63, Number 5, September 2003
Page(s) 722 - 728
Section Condensed matter: electronic structure, electrical, magnetic, and optical properties
Published online 01 November 2003
DOI: 10.1209/epl/i2003-00584-7
Europhys. Lett., 63 (5) , pp. 722-728 (2003)

Antiferromagnetism and single-particle properties in the two-dimensional half-filled Hubbard model: Slater vs. Mott-Heisenberg

K. Borejsza and N. Dupuis

Laboratoire de Physique des Solides, CNRS UMR 8502 Université Paris-Sud, 91405 Orsay, France

(Received 17 March 2003; accepted in final form 25 June 2003)

We study antiferromagnetism and single-particle properties in the two-dimensional half-filled Hubbard model at low temperature. Collective spin fluctuations are governed by a non-linear sigma model that we derive from the Hubbard model for any value of the Coulomb repulsion. As the Coulomb repulsion increases, the ground state progressively evolves from a Slater to a Mott-Heisenberg antiferromagnet. At finite temperature, we find a metal-insulator transition between a pseudogap phase at weak coupling and a Mott-Hubbard insulator at strong coupling.

71.10.Fd - Lattice fermion models (Hubbard model, etc.).
71.10.Hf - Non-Fermi-liquid ground states, electron phase diagrams and phase transitions in model systems.
71.27.+a - Strongly correlated electron systems; heavy fermions.

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