Dynamical vertex approximation for the two-dimensional Hubbard model

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS

卷:400

Article; Proceedings Paper

Schaefer, Thomas¹  Toschi, Alessandro¹  Held, Karsten¹ 

[1] TU Wien, Inst Solid State Phys, A-1040 Vienna, Austria

关键词: Strongly correlated electron systems;    Mott-Hubbard transition;   

DOI  :  10.1016/j.jmmm.2015.07.103

来源: Elsevier

【 摘 要 】

Recently, diagrammatic extensions of dynamical mean field theory (DMFT) have been proposed for including short- and long-range correlations beyond DMFT on an equal footing. We employ one of these, the dynamical vertex approximation (D Gamma A), and study the two-dimensional Hubbard model on a square lattice. We define two transition lines in the phase diagram which correspond, respectively, to the opening of the gap in the nodal direction and throughout the Fermi surface. Our self-energy data show that the evolution between the two regimes occurs in a gradual way (crossover) and also that at low enough temperatures the whole Fermi surface is always gapped. Furthermore, we present a comparison of our DTA calculations at a parameter set where data obtained by other techniques are available. (C) 2015 Elsevier B.V. All rights reserved.

【 授权许可】

Free