Strong anisotropy of electron-phonon interaction in NbP probed by magnetoacoustic quantum oscillations

TL;DR

This paper investigates the anisotropic electron-phonon interactions in NbP using magnetoacoustic quantum oscillations, revealing strong directional dependence and providing detailed Fermi surface insights beyond traditional methods.

Contribution

It demonstrates the use of ultrasound-based quantum oscillations to probe anisotropic electron-phonon interactions and Fermi surface features in NbP, offering a novel approach compared to magnetization or resistivity measurements.

Findings

Strong anisotropy of the effective deformation potential, up to 9 eV.

Observation of quantum oscillations in ultrasound velocity and attenuation.

Enhanced Fermi surface characterization through frequency filtering and Landau level tracing.

Abstract

In this study, we report on the observation of de Haas-van Alphen-type quantum oscillations (QO) in the ultrasound velocity of NbP as well as `giant QO' in the ultrasound attenuation in pulsed magnetic fields. The difference of the QO amplitude for different acoustic modes reveals a strong anisotropy of the effective deformation potential, which we estimate to be as high as $9\,\mathrm{eV}$ for certain parts of the Fermi surface. Furthermore, the natural filtering of QO frequencies and the tracing of the individual Landau levels to the quantum limit allows for a more detailed investigation of the Fermi surface of NbP as was previously achieved by means of analyzing QO observed in magnetization or electrical resistivity.