Recently an exact SU(2)\ensuremath{\bigotimes}SU(2) symmetry for the half-filled Hubbard model has been elucidated but has not yet been properly incorporated in many analyses of this model. We compute the irreducible representations of the symmetry group, a necessary step for any consistent mean-field analysis. A proper mean-field theory valid for both negative- and positive-U Hubbard models is then presented. A by-product of the description is a systematic enumeration of the Lie group SU(8) of unitary canonical transformations that is a direct generalization of the SU(4) transformation in the theory of superfluid $^{3}\mathrm{He}$ and the SU(2) Bogoliubov transformation in BCS theory.Recently an exact SU(2)\ensuremath{\bigotimes}SU(2) symmetry for the half-filled Hubbard model has been elucidated but has not yet been properly incorporated in many analyses of this model. We compute the irreducible representations of the symmetry group, a necessary step for any consistent mean-field analysis. A proper mean-field theory valid for both negative- and positive-U Hubbard models is then presented. A by-product of the description is a systematic enumeration of the Lie group SU(8) of unitary canonical transformations that is a direct generalization of the SU(4) transformation in the theory of superfluid $^{3}\mathrm{He}$ and the SU(2) Bogoliubov transformation in BCS theory.

Physical Review LettersSep 14, 199220 citations

Dynamical Mean Field Study of the Extended Hubbard Model

A. Baldwin, Alexandru Macridin, Mark Jarrell +1 more

Bulletin of the American Physical SocietyMar 16, 20060 citations

Mean‐Field Theory of an Extended Hubbard Model

Elka Korutcheva

physica status solidi (b)Oct 1, 19890 citations

Universality Class of the Antiferromagnetic Transition in the Two Dimensional Hubbard Model

F. Guinea, Enrique Louis, María P. López-Sancho +1 more

Abstract. The antiferromagnetic transition of the two dimensional Hubbard model is analyzed by comparing the available exact, numerical and mean field results. It is argued that all data is compatible with the opening of a mean field gap in a Fermi liquid of spin polarons, the so called Slater type of transition. In particular, this hypothesis explains the unusual dispersion relation of the quasiparticle bands near the transition. PACS. 71.10.Fd Lattice fermion models (Hubbard model, etc.) – 71.30.+h Metal-insulator transitions and other electronic transitions The nature of the insulating phase of the Hubbard model has attracted a great deal of attention. A clarification of the universality class of the transition will greatly help in understanding the nature of the “metallic ”, gapless phase away from half doping. A detailed discussion of the issue can be found in [1]. Opposing viewpoints on the problem are presented in [2,3]. An appealing approach is the scaling analysis discussed in [1]. It is assumed thatAbstract. The antiferromagnetic transition of the two dimensional Hubbard model is analyzed by comparing the available exact, numerical and mean field results. It is argued that all data is compatible with the opening of a mean field gap in a Fermi liquid of spin polarons, the so called Slater type of transition. In particular, this hypothesis explains the unusual dispersion relation of the quasiparticle bands near the transition. PACS. 71.10.Fd Lattice fermion models (Hubbard model, etc.) – 71.30.+h Metal-insulator transitions and other electronic transitions The nature of the insulating phase of the Hubbard model has attracted a great deal of attention. A clarification of the universality class of the transition will greatly help in understanding the nature of the “metallic ”, gapless phase away from half doping. A detailed discussion of the issue can be found in [1]. Opposing viewpoints on the problem are presented in [2,3]. An appealing approach is the scaling analysis discussed in [1]. It is assumed that

Jan 18, 19990 citations

New mean field theories of the Hubbard model

H.R. Krishn Amurthy, Ciriyam Jayaprakash, Wolfgang Wenzel +1 more

Physica C SuperconductivityDec 1, 19890 citations

^{3}\mathrm{He}

and the SU(2) Bogoliubov transformation in BCS theory.