Superconductivity from a long-range interaction: a crossover between the electron gas and the lattice model

Abstract

We explore how the superconductivity arising from the on-site electron-electron repulsion will change when the repulsion is changed to a long-ranged, 1/r-like one by introducing an extended Hubbard model with the repulsion extending to distant (12th) neighbors. With a simplified fluctuation-exchange approximation, we have found for the square lattice that (i) as the band filling becomes dilute enough, the charge susceptibility becomes comparable with the spin susceptibility, where p and then s pairings become dominant, in agreement with the result for the electron gas by Takada, while (ii) the d-wave, which reflects the lattice structure, dominates well away from the half filling. All these can be understood in terms of the spin and charge structures along with the shape and size of the Fermi surface.

5 pages, 6 figures

References in corpus (6)

• Systematic study of d-wave superconductivity in the 2D repulsive Hubbard model
• Superconductivity mediated by charge fluctuations in layered molecular crystals
• Phase diagram of the two-dimensional extended Hubbard model: Phase transitions between different pairing symmetries when charge and spin fluctuations coexist
• Superconductivity in Na_xCoO_2yH_2O by charge fluctuation
• Charge fluctuation induced superconducting state in two-dimensional quarter-filled electron systems
• Off-site-repulsion induced Triplet Superconductivity: a possibility of chiral p${}_{x+y}$ pairing in Sr${}_2$RuO${}_4$

Cited by in corpus (6)

• Electrically controlled superconducting states at the heterointerface SrTiO${}_3$/LaAlO${}_3$
• Polar Charge Fluctuation and Superconductivity in Organic Conductor
• Strong Coupling Expansion of the Extended Hubbard Model with Spin-Orbit Coupling
• Topological Superconductivity without Proximity Effect
• $d_{x^2-y^2}$-wave density wave and $d_{x^2-y^2}$-wave superconducting gap on the extended Hubbard model on a square lattice
• Density Matrix Renormalization Group study of superconducting pairing near the quarter-filled Wigner crystal