Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Journal of Physics C Solid State Physics

Superconductivity in the Hubbard model-a new functional integral approach

D. Schmeltzer

Published Feb 29, 1988• 1 citation
Publisher

Abstract

Using a functional integral method the author shows that the Hubbard model has a superconducting solution for the nonhalf-filled band case.
DOI
10.1088/0022-3719/21/6/007

Related papers

Electrical Conductivity in the Hubbard Model Using the Functional Integral Technique

GERD RÖPKE, Thomas Frauenheim, Walther Schiller

physica status solidi (b)•Apr 1, 1976•3 citations

Finite-Temperature Optical Conductivity of the Two-Dimensional Hubbard Model

Wenzhu Li, Feng Chen, Tiefeng Xu +1 more

The finite-temperature optical conductivity of the two-dimensional Hubbard model is studied by means of the grand canonical quantum Monte Carlo method. Results are reported for the half-filled and nonhalf-filled band. The formation and variation of Hubbard gap are observed. For the half-filled band case, our results support that there exists a high-temperature insulator-metal transition.

Communications in Theoretical Physics•Oct 30, 1994•1 citation

On the superconductivity existence within the Hubbard model

Anh Tuan Hoang, Toan Thang Nguyen, Ngoc Thuan Nguyen

Unknown eBooks•Sep 1, 1992•0 citations

From a Hubbard dimer to a Hubbard model in d dimensions: a path integral solution

Arkady L. Kholodenko

A new analytical method is proposed for solving the Hubbard model in d-dimensions. The method permits, in principle, the study of the Hubbard model at any temperature and any band filling. The accuracy of the method is tested against known Bethe ansatz results of Lieb and Wu (1968), and against known weak- and strong-coupling expansion results. The one-dimensional path integral solution obtained for the ground-state (half-filled band case) is in excellent qualitative agreement with Bethe ansatz results for all couplings and exactly reproduces weak- and strong-coupling expansion results.

Journal of Physics Condensed Matter•Jan 9, 1989•2 citations

On the existence of superconductivity in the Hubbard model

N. N. Bogolyubov, V. A. Moskalenko

Theoretical and Mathematical Physics•Jan 1, 1991•30 citations

Quasiparticle interactions in the infinite U Hubbard model.

Wei-neng Huang

The auxiliary boson method and 1/N expansion are applied to the solution of the Hubbard model in the U = $\infty$ limit, in functional integral form. The zero order term in the expansion gives the mean-field result of non-interacting enhanced mass quasiparticles, and the next order gives Gaussian fluctuations around the mean-field value, representing effective interactions between the quasiparticles. From the density-density correlation function, the collective mode indicates a very different behavior away from and close to half filling. The superconducting instability is examined to 1/$N\sp2$ order from the dominant double collective mode exchange. For a parabolic band, there is a p-wave triplet instability. But for a 2D square lattice, there is no superconducting pairing to this order. The effects of disorder on this system are also investigated. For moderate filling, the specific heat and scattering rate have the same results as predicted in the weakly interacting theories. Close to half-filling, the specific heat and scattering rate show a much sharper temperature and energy dependence.

•Jan 1, 1992•0 citations
A new analytical method is proposed for solving the Hubbard model in d-dimensions. The method permits, in principle, the study of the Hubbard model at any temperature and any band filling. The accuracy of the method is tested against known Bethe ansatz results of Lieb and Wu (1968), and against known weak- and strong-coupling expansion results. The one-dimensional path integral solution obtained for the ground-state (half-filled band case) is in excellent qualitative agreement with Bethe ansatz results for all couplings and exactly reproduces weak- and strong-coupling expansion results.
The auxiliary boson method and 1/N expansion are applied to the solution of the Hubbard model in the U = ∞\infty∞ limit, in functional integral form. The zero order term in the expansion gives the mean-field result of non-interacting enhanced mass quasiparticles, and the next order gives Gaussian fluctuations around the mean-field value, representing effective interactions between the quasiparticles. From the density-density correlation function, the collective mode indicates a very different behavior away from and close to half filling. The superconducting instability is examined to 1/$N\sp2$ order from the dominant double collective mode exchange. For a parabolic band, there is a p-wave triplet instability. But for a 2D square lattice, there is no superconducting pairing to this order. The effects of disorder on this system are also investigated. For moderate filling, the specific heat and scattering rate have the same results as predicted in the weakly interacting theories. Close to half-filling, the specific heat and scattering rate show a much sharper temperature and energy dependence.