scholarly journals Evolution of one-particle and double-occupied Green functions for the Hubbard model, with interaction, at half-filling with lifetime effects within the moment approach

1999 ◽  
Vol 60 (8) ◽  
pp. 5366-5374
Author(s):  
S. Schafroth ◽  
J. J. Rodríguez-Núñez
Keyword(s):  
Hubbard Model ◽  
Green Functions ◽  
Half Filling ◽  
Moment Approach ◽  
The Moment ◽  
Lifetime Effects

Study of the Hubbard model at half filling

2008 ◽  
Vol 154 (1) ◽  
pp. 52-63 ◽  
Author(s):  
Yu. A. Izyumov ◽  
N. I. Chashchin
Keyword(s):  
Hubbard Model ◽  
Half Filling

Phase diagram of an extended Hubbard model with correlated hopping at half filling

1995 ◽  
Vol 51 (19) ◽  
pp. 13774-13777 ◽  
Author(s):  
A. A. Aligia ◽  
Liliana Arrachea ◽  
E. R. Gagliano
Keyword(s):  
Phase Diagram ◽  
Hubbard Model ◽  
Extended Hubbard Model ◽  
Half Filling

scholarly journals Self-Consistent Calculation of Particle-Hole Diagrams on the Matsubara Frequency: Flex Approximation

1997 ◽  
Vol 08 (05) ◽  
pp. 1145-1158
Author(s):  
J. J. Rodríguez-Núñez ◽  
S. Schafroth
Keyword(s):  
Hubbard Model ◽  
Imaginary Part ◽  
Chemical Potential ◽  
Order Approximation ◽  
The Self ◽  
Green Functions ◽  
Matsubara Frequency ◽  
Self Energy ◽  
Peak Structure ◽  
Self Consistent

We implement the numerical method of summing Green function diagrams on the Matsubara frequency axis for the fluctuation exchange (FLEX) approximation. Our method has previously been applied to the attractive Hubbard model for low density. Here we apply our numerical algorithm to the Hubbard model close to half filling (ρ =0.40), and for T/t = 0.03, in order to study the dynamics of one- and two-particle Green functions. For the values of the chosen parameters we see the formation of three branches which we associate with the two-peak structure in the imaginary part of the self-energy. From the imaginary part of the self-energy we conclude that our system is a Fermi liquid (for the temperature investigated here), since Im Σ( k , ω) ≈ w2 around the chemical potential. We have compared our fully self-consistent FLEX solutions with a lower order approximation where the internal Green functions are approximated by free Green functions. These two approches, i.e., the fully self-consistent and the non-self-consistent ones give different results for the parameters considered here. However, they have similar global results for small densities.

Class of variational singlet wave functions for the Hubbard model away from half filling

1989 ◽  
Vol 40 (13) ◽  
pp. 8939-8944 ◽  
Author(s):  
P. W. Anderson ◽  
B. S. Shastry ◽  
D. Hristopulos
Keyword(s):  
Hubbard Model ◽  
Wave Functions ◽  
Half Filling

Spectral functions in the hubbard model with half-filling

2004 ◽  
Vol 46 (8) ◽  
pp. 1469-1473 ◽  
Author(s):  
S. G. Ovchinnikov ◽  
E. I. Shneider
Keyword(s):  
Hubbard Model ◽  
Spectral Functions ◽  
Half Filling

scholarly journals The Moment Sum Rule and Its Consequences for Ferromagnetism in the Hubbard Model

1998 ◽  
Vol 210 (1) ◽  
pp. 199-228 ◽  
Author(s):  
M. Potthoff ◽  
T. Herrmann ◽  
T. Wegner ◽  
W. Nolting
Keyword(s):  
Hubbard Model ◽  
Sum Rule ◽  
The Moment
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