Generation of d-wave coupling in the two-dimensional Hubbard model from functional renormalization

TL;DR

This paper investigates how antiferromagnetic fluctuations induce d-wave pairing in the 2D Hubbard model using functional renormalization group methods, proposing an effective bosonic model for the interactions.

Contribution

It introduces a scale-dependent bosonization approach for the d-wave coupling and proposes an effective model based on collective bosons exchange.

Findings

Antiferromagnetic fluctuations induce d-wave pairing in the model.

A bosonization method captures the momentum-dependent d-wave coupling.

An effective coarse-grained model is proposed for the Hubbard system.

Abstract

Within the two-dimensional repulsive t-t'-Hubbard model, an attractive coupling in the d-wave pairing channel is induced by antiferromagnetic fluctuations. We investigate this coupling using functional renormalization group equations. The momentum dependent d-wave coupling can be bosonized by the use of scale dependent field transformations. We propose an effective coarse grained model for the Hubbard model which is based on the exchange of antiferromagnetic and d-wave collective bosons.