Ultrasonic attenuation in d-wave superconductors

TL;DR

This paper investigates how ultrasonic attenuation varies in d-wave superconductors at low temperatures, showing it depends on propagation direction and can reveal node positions in the Fermi surface.

Contribution

It proposes using ultrasonic attenuation measurements in single crystals to determine the location of nodes in high-Tc d-wave superconductors.

Findings

Attenuation ratio depends on propagation direction.

Maxima in attenuation correspond to order parameter nodes.

Method to identify node positions via ultrasonic measurements.

Abstract

The longitudinal ultrasonic attenuation at low temperatures for a $d$-wave superconducting order parameter is examined. The ratio of the superconducting to normal state attenuation, $\alpha_{s}/\alpha_{n}$, depends strongly on the direction of propagation of ultrasound with maxima corresponding to nodes of the order parameter on the Fermi surface. We propose that measurements of ultrasonic attenuation in a single crystal of the high-$T_{c}$ superconductors can give the information regarding the position of nodes.