Spin density wave fluctuations and p-wave pairing in Sr2RuO4

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Materials

Background:

• Sr(2)RuO4 exhibits chiral p-wave superconductivity, a phenomenon of significant theoretical interest.
• A debate exists regarding whether the two-dimensional gamma band or the one-dimensional alpha, beta bands are responsible for this superconductivity.
• The alpha, beta bands are associated with spin density wave (SDW) fluctuations, complicating the understanding of the superconducting mechanism.

Purpose of the Study:

• To resolve the debate concerning the active Fermi surface component driving chiral p-wave superconductivity in Sr(2)RuO4.
• To investigate the role of spin density wave (SDW) fluctuations in quasi-one-dimensional systems.
• To elucidate the relationship between SDW fluctuations and p-wave pairing in the context of Sr(2)RuO4's electronic structure.

Main Methods:

• Application of renormalization group (RG) theory.
• Analysis of quasi-one-dimensional repulsive Hubbard chains.
• Modeling of incommensurate spin density wave (SDW) fluctuations and their nesting Fermi surface properties.

Main Results:

• The renormalization group theory successfully explains the form of spin density wave (SDW) fluctuations in quasi-one-dimensional systems.
• The study reconciles the absence of long-range magnetic order with the presence of nesting-induced SDW fluctuations.
• A mutual exclusion between p-wave pairing and SDW fluctuations was identified in the studied repulsive Hubbard chains.

Conclusions:

• The findings favor the assignment of the two-dimensional gamma band as the source of chiral p-wave pairing in Sr(2)RuO4.
• The one-dimensional alpha, beta bands, associated with SDW fluctuations, are unlikely to be the primary drivers of superconductivity.
• This work provides a theoretical framework for understanding the interplay between magnetic fluctuations and superconductivity in correlated materials.