Linked‐cluster expansion for the single‐band Hubbard model

1991 ◽  
Vol 69 (8) ◽  
pp. 4656-4658 ◽  
Author(s):  
Kok‐Kwei Pan ◽  
Yung‐Li Wang
Keyword(s):  
Hubbard Model ◽  
Cluster Expansion ◽  
Single Band

PHASE SEPARATION IN THE TWO-DIMENSIONAL HUBBARD MODEL

2005 ◽  
Vol 19 (01n03) ◽  
pp. 299-302 ◽  
Author(s):  
M. YU ◽  
H. Q. LIN
Keyword(s):  
Phase Separation ◽  
Hubbard Model ◽  
Coulomb Interaction ◽  
Single Band ◽  
Study Phase ◽  
Two Dimensional ◽  
Stripe Phase ◽  
Hartree Fock ◽  
Band Filling

In this paper, we study phase separation in the two-dimensional single-band Hubbard model with the unrestricted Hartree-Fock(UHF) method and the restricted Hartree-Fock (RHF) method. We perform the calculation for square lattices and rectangle lattices. It is observed that the stripe phase exists and it depends on three aspects: geometry of the lattice, Coulomb interaction U and band filling n. To gain more physical insights, we consider the Hubbard model with spin dependent hoppings: t↑ and t↓, and study the effect of varying [Formula: see text] on the phase separation.

scholarly journals One-particle spectral weight of the three-dimensional single-band Hubbard model

1996 ◽  
Vol 54 (23) ◽  
pp. 16523-16532 ◽  
Author(s):  
M. Ulmke ◽  
R. T. Scalettar ◽  
A. Nazarenko ◽  
E. Dagotto
Keyword(s):  
Hubbard Model ◽  
Three Dimensional ◽  
Spectral Weight ◽  
Single Band

X-Ray Absorption Spectra Reveal the Inapplicability of the Single-Band Hubbard Model to Overdoped Cuprate Superconductors

2009 ◽  
Vol 103 (8) ◽  
Author(s):  
D. C. Peets ◽  
D. G. Hawthorn ◽  
K. M. Shen ◽  
Young-June Kim ◽  
D. S. Ellis ◽  
...  
Keyword(s):  
Hubbard Model ◽  
Absorption Spectra ◽  
Cuprate Superconductors ◽  
Single Band ◽  
X Ray ◽  
X Ray Absorption

A VARIATIONAL THEORY OF QUASI-PARTICLES IN A 3D N x N x N CUBIC LATTICE

2014 ◽  
Vol 5 (1) ◽  
pp. 712-725
Author(s):  
Enaibe A. Edison ◽  
Akpata Erhieyovwe ◽  
Osafile Omosede
Keyword(s):  
Hubbard Model ◽  
Coulomb Interaction ◽  
Interaction Strength ◽  
Finite Size ◽  
Electron System ◽  
Single Band ◽  
Variational Theory ◽  
S Wave ◽  
Cubic Lattice ◽  
Hubbard Hamiltonian

The single-band Hubbard Hamiltonian study faces a serious limitation and difficulty as we move away from finite - size lattices to larger N - dimensional lattices. Thus there is the needto develop the means of overcoming the finite - size lattice defects as we pass on to a higher dimension.In this work, a quantitative approximation to the one-band Hubbard model is presented using a variational analytic approach. The goal of this work, therefore, is to explore quantitatively the lowest ground-state energy and the pairing correlations in 3D N x N x N lattices of the Hubbard model. We developed the unit step model as an approximate solution to the single-band Hubbard Hamiltonian to solve variationallythe correlation of two interacting elections on a three-dimensional cubic lattice. We also showed primarily how to derive possible electronic states available for several even and odd3D lattices, although, this work places more emphasis on a 3D 5 x 5 x 5 lattice. The results emerging from our present study compared favourablywith the results of Gutzwillervariational approach (GVA) and correlated variational approach (CVA), at thelarge limit of the Coulomb interaction strength (U/4t). It is revealed in this study, that the repulsive Coulomb interaction which in part leads to the strong electronic correlations, would indicate that the two electron system prefer not to condense into s-wave superconducting singlet state (s = 0), at high positive values of the interaction strength.

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