scholarly journals Fermi surface evolution of the 2D Hubbard model within a novel four-pole approximation

AIP Advances ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 101327
Author(s):  
Andrea Di Ciolo ◽  
Adolfo Avella
Keyword(s):  
Fermi Surface ◽  
Hubbard Model ◽  
Pole Approximation ◽  
Surface Evolution

scholarly journals SPECTRAL FUNCTION OF A d-p HUBBARD MODEL

2011 ◽  
Vol 25 (01) ◽  
pp. 41-53 ◽  
Author(s):  
E. J. CALEGARI ◽  
S. G. MAGALHAES
Keyword(s):  
Correlation Function ◽  
Fermi Surface ◽  
Hubbard Model ◽  
Spectral Function ◽  
Coulomb Interaction ◽  
Green's Functions ◽  
Green’S Functions ◽  
Pole Approximation ◽  
Antiferromagnetic Correlations ◽  
Important Correlation

This work investigates a d-p Hubbard model by the n-pole approximation in the hole-doped regime. In particular, the spectral function A(ω, k) is analyzed varying the filling, the local Coulomb interaction and the d-p hybridization. It should be remarked that the original n-pole approximation (Phys. Rev.184, 451 1969) has been improved in order to include adequately the k-dependence of the important correlation function 〈Sj·Si〉 present in the poles of the Green's functions. It has been verified that the topology of the Fermi surface (defined by A(ω = 0, k)) is deeply affected by the doping, the strength of the Coulomb interaction and also by the hybridization. Particularly, in the underdoped regime, the spectral function A(ω = 0, k) presents very low intensity close to the antinodal points (0, ±π) and (±π, 0). Such a behavior produces an anomalous Fermi surface (pockets) with pseudogaps in the region of the antinodal points. On the other hand, if the d-p hybridization is enhanced sufficiently, such pseudogaps vanish. It is precisely the correlation function 〈Sj·Si〉, present in the poles of the Green's functions, plays an important role in the underdoped situation. In fact, antiferromagnetic correlations coming from 〈Sj·Si〉 strongly modify the quasiparticle band structure. This is the ultimate source of anomalies in the Fermi surface in the present approach.

Numerical Study of the Fermi Surface Evolution in Cuprates Using the One-Band Hubbard Model

2020 ◽  
Vol 840 ◽  
pp. 507-513
Author(s):  
Lanang Maulana Aminullah ◽  
Iman Santoso
Keyword(s):  
Fermi Surface ◽  
Hubbard Model ◽  
Order Parameter ◽  
Energy Gap ◽  
Numerical Study ◽  
Experimental Result ◽  
Range Interaction ◽  
Surface Evolution ◽  
Specific Order ◽  
The One

A Numerical calculation of the Fermi Surface (FS) evolution in cuprate using the one-band Hubbard model by the matrix diagonalization method has been done. This work focusses on the study of the evolution of the FS in the cuprate material, namely , numerically by introducing a specific order parameter in the Hubbard model matrix. In this study, we confirm two evolution types of the FS of as an experimental result. Firstly, the evolution of the antibonding FS topology from the electron-like to the hole-like is generated by the order parameter that has a form of where is the order parameter coefficient that corresponds to the hopping parameter of the atomic neighbor long-range interaction and is the normalized momenta coordinate of the first Brillouin zone. On the contrary, the order parameter that has a form of generates the evolution of the FS from the hole-like topology to the electron-like topology. Secondly, the anisotropic evolution of the FS can be described by an extended d-wave order parameter which generating either the V-shape or U-shape type of the energy gap.

scholarly journals Fermi surface evolution across multiple charge density wave transitions inErTe3

2010 ◽  
Vol 81 (7) ◽  
Author(s):  
R. G. Moore ◽  
V. Brouet ◽  
R. He ◽  
D. H. Lu ◽  
N. Ru ◽  
...  
Keyword(s):  
Fermi Surface ◽  
Charge Density ◽  
Charge Density Wave ◽  
Density Wave ◽  
Surface Evolution ◽  
Multiple Charge

scholarly journals Pseudogap and the specific heat of high Tcsuperconductors: a Hubbard model in a n-pole approximation

2015 ◽  
Vol 592 ◽  
pp. 012075
Author(s):  
E J Calegari ◽  
A C Lausmann ◽  
S G Magalhaes ◽  
C M Chaves ◽  
A Troper
Keyword(s):  
Hubbard Model ◽  
Specific Heat ◽  
Pole Approximation

Fermi surface evolution in the ensemble of spin-polarized quasiparticles in La2 − x Sr x CuO4

JETP Letters ◽  
2014 ◽  
Vol 98 (9) ◽  
pp. 528-533 ◽  
Author(s):  
D. M. Dzebisashvili ◽  
V. V. Val’kov ◽  
A. F. Barabanov
Keyword(s):  
Fermi Surface ◽  
Surface Evolution ◽  
Spin Polarized
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