Determining the superconducting gap structure in Sr2RuO4 from sound attenuation studies below Tc

TL;DR

This study uses sound attenuation measurements to identify and differentiate the nodal structures of multiple bands in the unconventional superconductor Sr2RuO4 below its transition temperature.

Contribution

It provides a quantitative theoretical framework showing how sound attenuation can distinguish different nodal structures on various bands in Sr2RuO4.

Findings

Sound attenuation can identify different nodal structures on separate bands.

Both b3 and b1/b2 bands have point nodes, with distinct quantitative features.

The study offers a method to analyze multiband superconductors' gap structures.

Abstract

This work presents a quantitative theoretical study of the sound attenuation in the unconventional multiband superconductor Sr2RuO4 below the superconducting transition temperature Tc. Sound attenuation in this material is shown to have the remarkable property of being able to identify different nodal structures on different bands. The nodal structures on the \gamma band on the one hand, and on the \alpha and \beta bands on the other, are both found to be characterized by the existence of point nodes, but are significantly different in their quantitative aspects.