Spin-fluctuation exchange study of superconductivity in two- and three-dimensional single-band Hubbard models

TL;DR

This study investigates how spin fluctuations influence superconductivity in 2D and 3D single-band Hubbard models, revealing that d-wave pairing is more robust in 2D and p-wave pairing is comparatively weak.

Contribution

It provides a comparative analysis of spin-fluctuation mediated pairing in different dimensions within the Hubbard model using the fluctuation exchange approximation.

Findings

d-wave pairing is stronger in 2D than in 3D

p-wave pairing is significantly weaker than d-wave

superconductivity is more favorable in two-dimensional systems

Abstract

In order to identify the most favorable situation for superconductivity in the repulsive single-band Hubbard model, we have studied instabilities for d-wave pairing mediated by antiferromagnetic spin fluctuations and p-pairing mediated by ferromagnetic fluctuations with the fluctuation exchange approximation in both two dimensions and three dimensions. By systematically varying the band filling and band structure we have shown that (i) d-pairing is stronger in two dimensions than in three dimensions, and (ii) p-pairing is much weaker than the d-pairing.