scholarly journals Ionic Hubbard model on a triangular lattice forNa0.5CoO2,Rb0.5CoO2, andK0.5CoO2: Mean-field slave boson theory

2009 ◽  
Vol 80 (8) ◽  
Author(s):  
B. J. Powell ◽  
J. Merino ◽  
Ross H. McKenzie
Keyword(s):  
Hubbard Model ◽  
Triangular Lattice ◽  
Mean Field ◽  
Boson Theory ◽  
Ionic Hubbard Model

PHASE TRANSITION IN THE HALF-FILLED IONIC HUBBARD MODEL: MEAN-FIELD SLAVE BOSON STUDY

2012 ◽  
Vol 26 (03) ◽  
pp. 1150016 ◽  
Author(s):  
DUC-ANH LE ◽  
ANH-TUAN HOANG
Keyword(s):  
Hubbard Model ◽  
Mean Field ◽  
Coulomb Repulsion ◽  
Mott Insulator ◽  
Metallic Phase ◽  
Electronic Phase ◽  
Paramagnetic Solution ◽  
Boson Theory ◽  
Zero Values ◽  
Ionic Hubbard Model

We study electronic phase transitions in the half-filled ionic Hubbard model with an on-site Coulomb repulsion U and an ionic energy Δ by using the Kotliar–Ruckenstein slave-boson theory. Assuming a paramagnetic solution, we show that for any non-zero values of Δ, with increasing U the system undergoes a transition from band-insulator to Mott-insulator. Our results have implied the absence of a metallic phase between the band and the Mott insulator phases.

Mott Transition in the Mass Imbalanced Ionic Hubbard Model at Half Filling

2019 ◽  
Vol 29 (3SI) ◽  
pp. 305
Author(s):  
Nguyen Thi Hai Yen ◽  
Le Duc Anh ◽  
Hoang Anh Tuan ◽  
Nguyen Toan Thang
Keyword(s):  
Field Theory ◽  
Hubbard Model ◽  
Mean Field Theory ◽  
Mean Field ◽  
Dynamical Mean Field Theory ◽  
Mass Imbalance ◽  
Half Filling ◽  
Ionic Hubbard Model ◽  
Ionic Energy ◽  
Good Agreement

The Mott - Hubbard metal - insulator transition in the half-filled mass imbalanced ionic Hubbard model is investigated using the two-site dynamical mean field theory. We find that for a fixed mass imbalanced parameter r the critical interaction Uc increases when the ionic energy \(\Delta\) is increased. In the other hand, for a fixed \(\Delta\), \(U_c\) decreases with increasing the mass imbalance. We also show the existence of BI phase in the system for the case \(\Delta \ne 0\), \(U=0\) and calculate the staggered charge density \(n_B − n_A\) as a function of the interaction for different values of the mass imbalance. Our results in the limiting cases (\(r = 1\); \(\Delta \ne 0\) or/and \(\Delta = 0\); \(r\ne 1\)) are in good agreement with those obtained from full dynamical mean field theory.

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