Spin Density Wave Fluctuations and p-wave Pairing in Sr2RuO4

TL;DR

This paper investigates the origin of p-wave superconductivity in Sr2RuO4, suggesting it arises from the gamma-band, by analyzing SDW fluctuations and their relation to Fermi surface nesting using renormalization group theory.

Contribution

It applies renormalization group theory to quasi-one-dimensional Hubbard chains to clarify the relationship between SDW fluctuations and p-wave pairing in Sr2RuO4.

Findings

SDW fluctuations are explained by nesting in the (alpha,beta) bands.

Mutual exclusion of SDW and p-wave pairing supports gamma-band as the pairing source.

Renormalization group analysis reconciles absence of SDW order with nesting features.

Abstract

Recently a debate has arisen over which of the two distinct parts of the Fermi surface of Sr2RuO4, is the active part for the chiral p-wave superconductivity. Early theories proposed p-wave pairing on the two dimensional gamma-band, while a recent proposal focuses on the one dimensional (alpha,beta) bands whose nesting pockets are the source of the strong incommensurate spin density wave (SDW) fluctuations. We apply a renormalization group theory to study quasi-one dimensional repulsive Hubbard chains and explain the form of SDW fluctuations, reconciling the absence of long range order with their nesting Fermi surface. The mutual exclusion of p-wave pairing and SDW fluctuations in repulsive Hubbard chains favors the assignment of the two dimensional gamma-band as the source of p-wave pairing.