We consider a Hubbard model on a square lattice with an additional interaction, $W$ , which depends upon the square of the near-neighbor hopping. At half filling and a constant value of the Hubbard repulsion, increasing the strength of the interaction $W$ drives the system from an antiferromagnetic Mott insulator to a ${d}_{{x}^{2}{\ensuremath{-}y}^{2}}$ superconductor. This conclusion is reached on the basis of zero temperature quantum Monte Carlo simulations on lattice sizes up to $16\ifmmode\times\else\texttimes\fi{}16$.We consider a Hubbard model on a square lattice with an additional interaction, $W$, which depends upon the square of the near-neighbor hopping. At half filling and a constant value of the Hubbard repulsion, increasing the strength of the interaction $W$ drives the system from an antiferromagnetic Mott insulator to a ${d}_{{x}^{2}{\ensuremath{-}y}^{2}}$ superconductor. This conclusion is reached on the basis of zero temperature quantum Monte Carlo simulations on lattice sizes up to $16\ifmmode\times\else\texttimes\fi{}16$.

arXiv:cond-mat/9609034Physical Review LettersNov 25, 199655 citations

d-wave Pairing in the Two-Dimensional Hubbard Model

Douglas J. Scalapino

Bulletin of the American Physical SocietyMar 14, 20060 citations

Superconductivity from a Long-Range Repulsive Interaction

Seiichiro Onari, Ryotaro Arita, K. Kuroki +1 more

The lattice model with short‐range interactions (exemplified by the Hubbard model) is known to exhibit quite different features from those in the electron gas with the long‐range Coulomb interaction. In order to explore how they cross over to each other, we have studied an extended Hubbard model which includes repulsions up to the 12th neighbors with the simplified fluctuation exchange (FLEX) approximation for the square lattice. We have found that (i) in the most dilute density region, spin and charge fluctuations become comparable, and s‐ and p‐waves superconductivity become dominant, in agreement with the result for the electron gas by Takada, while (ii) the dominant spin fluctuation and its reflection on dx2−y2 and dxy pairing, both the effect of lattice structure, persists well away (n ≳ 0.2) from the half filling. © 2006 American Institute of PhysicsThe lattice model with short‐range interactions (exemplified by the Hubbard model) is known to exhibit quite different features from those in the electron gas with the long‐range Coulomb interaction. In order to explore how they cross over to each other, we have studied an extended Hubbard model which includes repulsions up to the 12th neighbors with the simplified fluctuation exchange (FLEX) approximation for the square lattice. We have found that (i) in the most dilute density region, spin and charge fluctuations become comparable, and s‐ and p‐waves superconductivity become dominant, in agreement with the result for the electron gas by Takada, while (ii) the dominant spin fluctuation and its reflection on dx2−y2 and dxy pairing, both the effect of lattice structure, persists well away (n ≳ 0.2) from the half filling. © 2006 American Institute of Physics

AIP conference proceedingsJan 1, 20060 citations

A MEAN FIELD APPROACH TO THE COLORED HUBBARD MODEL

Tobias Baier, Eike Bick

By subdividing a 2d square lattice into plaquettes containing 4 lattice sites each, the Hubbard Hamiltonian is reformulated in terms of different "colored" fermion species. This makes it possible to describe e.g. antiferromagnetic order or d-wave superconductivity in terms of expectation values of composite scalar fields. A suitable mean field approximation indeed reproduces qualitatively the measured phase diagram and shows a competition between phases with antiferromagnetic ordering and dx2-y2-superconductivity at low temperatures.By subdividing a 2d square lattice into plaquettes containing 4 lattice sites each, the Hubbard Hamiltonian is reformulated in terms of different "colored" fermion species. This makes it possible to describe e.g. antiferromagnetic order or d-wave superconductivity in terms of expectation values of composite scalar fields. A suitable mean field approximation indeed reproduces qualitatively the measured phase diagram and shows a competition between phases with antiferromagnetic ordering and dx2-y2-superconductivity at low temperatures.

International Journal of Modern Physics AApr 30, 20010 citations

We consider a Hubbard model on a square lattice with an additional interaction,

W

, which depends upon the square of the near-neighbor hopping. At half filling and a constant value of the Hubbard repulsion, increasing the strength of the interaction

W

drives the system from an antiferromagnetic Mott insulator to a ${d}_{{x}^{2}{\ensuremath{-}y}^{2}}$ superconductor. This conclusion is reached on the basis of zero temperature quantum Monte Carlo simulations on lattice sizes up to $16\ifmmode\times\else\texttimes\fi{}16$.