We calculate the one-particle density of states for the Mott–Hubbard insulating phase of the Hubbard model on a Bethe lattice in the limit of infinite coordination number. We employ the Kato–Takahashi perturbation theory around the strong-coupling limit to derive the Green function. We show that the Green function for the lower Hubbard band can be expressed in terms of polynomials in the bare h...

The one-dimensional Hubbard model is known to possess an extended su(2) symmetry and to be integrable. I introduce an integrable model with an extended su(n) symmetry. This model contains the usual su(2) Hubbard model and has a set of features that makes it the natural su(n) generalization of the Hubbard model. Complete integrability is shown by introducing the L-matrix and showing that the tra...

G. G. Batrouni, H. R. Krishnamurthy, K. W. Mahmud, V. G. Rousseau, and R. T. Scalettar INLN, Université de Nice-Sophia Antipolis, CNRS; 1361 route des Lucioles, 06560 Valbonne, France Physics Department, University of California, Davis, California 95616, USA Centre for Condensed Matter Theory, Department of Physics, Indian Institute of Science, Bangalore 560012, India Lorentz Institute, Leiden ...

a finite chain calculation in terms of hubbard x-operators is explored by setting up a vibronic harniltonian. the model conveniently transformed into a form so that in the case of strong coupling a numerical renormalization group approach is applicable. to test the technique, a one particle green function is calculated for the model harniltonian

We calculate the one-particle density of states for the Mott–Hubbard insulating phase of the Hubbard model on a Bethe lattice in the limit of infinite coordination number. We employ the Kato–Takahashi perturbation theory around the strong-coupling limit to derive the Green function. We show that the Green function for the lower Hubbard band can be expressed in terms of polynomials in the bare h...

A finite chain calculation in terms of Hubbard X-operators is explored by setting up a vibronic Harniltonian. The model conveniently transformed into a form so that in the case of strong coupling a numerical renormalization group approach is applicable. To test the technique, a one particle Green function is calculated for the model Harniltonian

Ferromagnetism in the Hubbard model with an infinite-range hopping. Abstract We prove, as recently conjectured, that the ground state of the Hub-bard Hamiltonian with an infinite-range hopping, when the number of electrons N e = N + 1 (N being the number of sites), is ferromagnetic fully polarized. Despite its long history, the problem of itinerant ferromagnetism is still, to many regards, an o...

We solve the periodic Anderson model in the Mott-Hubbard regime, using dynamical mean field theory. Upon electron doping of the Mott insulator, a metal-insulator transition occurs which is qualitatively similar to that of the single band Hubbard model, namely, with a divergent effective mass and a first order character at finite temperatures. Surprisingly, upon hole doping, the metal-insulator ...

We use the Random Dispersion Approximation (RDA) to study the Mott-Hubbard transition in the Hubbard model at half band filling. The RDA becomes exact for the Hubbard model in infinite dimensions. We implement the RDA on finite chains and employ the Lanczos exact diagonalization method in real space to calculate the ground-state energy, the average double occupancy, the charge gap, the momentum...

We develop a supersymmetric representation of the Hubbard operators which unifies the Slave Boson and Slave Fermion representations, allowing a second-quantized treatment of Hubbard operators with both symmetric and anti-symmetric character. We provide a simple example of the application of this method to the atomic limit of the Hubbard model and discuss its more general application to the infi...