Probing the d_{x2-y2}-wave Pomeranchuk instability by ultrasound

TL;DR

This paper investigates how ultrasound measurements can detect d_{x2-y2}-wave Pomeranchuk instabilities, revealing specific anisotropic attenuation signatures that can identify electronic nematic phases in materials like Sr3Ru2O7.

Contribution

It provides a theoretical analysis of ultrasound response rules to identify Pomeranchuk instabilities, especially the d_{x2-y2}-wave type, using a self-consistent renormalization approach.

Findings

Transverse sound attenuation along [110] is enhanced near the instability.

Attenuation along [100] remains unaffected by the fluctuations.

Results are applicable to Sr3Ru2O7 as a candidate for Pomeranchuk instability.

Abstract

Selection rules of ultrasound attenuation and sound velocity renormalization are analyzed in view of their potential application to identify Pomeranchuk instabilities (electronic nematic phase). It is shown that the transverse sound attenuation along [110] direction is enhanced by the Fermi surface fluctuations near a d_{x2-y2}-wave Pomeranchuk instability, while the attenuation along [100] direction remains unaffected. Moreover the fluctuation regime above the instability is analyzed by means of a self-consistent renormalization scheme. The results could be applied directly to Sr3Ru2O7 which is a potential candidate for a Pomeranchuk instability at its metamagnetic transition in strong magnetic fields.