The Hubbard model beyond the two-pole approximation: a composite operator method study

@article{Avella2014TheHM,
  title={The Hubbard model beyond the two-pole approximation: a composite operator method study},
  author={Adolfo Avella},
  journal={The European Physical Journal B},
  year={2014},
  volume={87},
  pages={1-18}
}
  • A. Avella
  • Published 31 January 2014
  • Physics
  • The European Physical Journal B
Within the framework of the Composite Operator Method, a three-pole solution for the two-dimensional Hubbard model is presented and analyzed in detail. In addition to the two Hubbard operators, the operatorial basis comprises a third operator describing electronic transitions dressed by nearest-neighbor spin fluctuations. These latter, compared to charge and pair fluctuations, are assumed to be preeminent in the region of model-parameter space — small doping, low temperature and large on-site… Expand
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References

SHOWING 1-10 OF 112 REFERENCES
The Hubbard model with intersite interaction within the Composite Operator Method
Abstract.We study the one- and two-dimensional extended Hubbard model by means of the Composite Operator Method within the 2-pole approximation. The fermionic propagator is computed fullyExpand
The 1D Hubbard model within the Composite Operator Method
Abstract:Although effective for two dimensional (2D) systems, some approximations may fail in describing the properties of one-dimensional (1D) models, which belong to a different universality class.Expand
High-order correlation effects in the two-dimensional Hubbard model
The electronic states of the two-dimensional Hubbard model are investigated by means of a 4-pole approximation within the composite operator method. In addition to the conventional Hubbard operators,Expand
COM framework for d-wave superconductivity in the 2D Hubbard model
Abstract The two-dimensional Hubbard model has been studied within the Composite Operator Method (COM) [1] starting from a basis made of the two Hubbard composite fields in the Nambu representationExpand
Underdoped cuprate phenomenology in the two-dimensional Hubbard model within the composite operator method
The two-dimensional Hubbard model is studied within the Composite Operator Method (COM) with the residual self-energy computed in the Self-Consistent Born Approximation (SCBA). COM describesExpand
Bosonic sector of the two-dimensional Hubbard model studied within a two-pole approximation
The charge and spin dynamics of the two-dimensional Hubbard model in the paramagnetic phase is first studied by means of the two-pole approximation within the framework of the composite operatorExpand
Single-particle dispersion of the 2D p–d model
Abstract The two-dimensional p–d model has been solved within the Composite Operator Method (COM) in an original four-pole approximation where the basic four-component composite field contains bothExpand
The Hubbard Model in the Two-Pole Approximation
The two-dimensional Hubbard model is analyzed in the framework of the two-pole expansion. It is demonstrated that several theoretical approaches, when considered at their lowest level, are allExpand
The Hubbard model within the equations of motion approach
The Hubbard model plays a special role in condensed matter theory as it is considered to be the simplest Hamiltonian model one can write in order to describe anomalous physical properties of someExpand
Numerical study of the two-dimensional Hubbard model.
TLDR
The results support the existence of long-range antiferromagnetic order in the ground state at half-Filling and its absence at quarter-filling and find evidence for an attractive effective /ital d/-wave pairing interaction near half- filling but have not found evidence for a phase transition to a superconducting state. Expand
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4
5
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