Magnetic versus nonmagnetic superconducting states in Sr$_2$RuO$_4$

TL;DR

This paper discusses the challenge of distinguishing magnetic from nonmagnetic superconducting states in Sr$_2$RuO$_4$ using ultrasonic resonance measurements, highlighting limitations in current methods.

Contribution

It clarifies that ultrasonic resonance intensity measurements cannot differentiate between magnetic and nonmagnetic two-component superconducting states in Sr$_2$RuO$_4$.

Findings

Ultrasonic resonance measurements are insufficient to distinguish superconducting states.

The study emphasizes the need for alternative methods to identify the nature of the superconducting state.

Current measurement techniques cannot conclusively determine the magnetic properties of the superconducting phase.

Abstract

The measurements of intensity of ultrasonic resonances below the transition to the superconducting state in a tetragonal metal cannot distinguish between the magnetic and nonmagnetic superconducting states with two-component order parameters.