Quantum oscillations in acoustic phonons in Weyl semimetals

TL;DR

This paper predicts that acoustic phonons in Weyl semimetals exhibit oscillatory behaviors in their dispersion and attenuation under magnetic fields, revealing information about the electronic structure and topological features.

Contribution

It provides a theoretical analysis of phonon spectrum modifications in Weyl semimetals due to electron-phonon interactions under magnetic fields, highlighting observable oscillations.

Findings

Phonon dispersion and attenuation oscillate with magnetic field.

Oscillation patterns vary with Fermi energy regimes.

Van Hove singularity causes transition in oscillation patterns.

Abstract

We theoretically study the modification of the energy spectrum of long-wavelength acoustic phonons due to the electron-phonon interaction in a three-dimensional topological Weyl semimetal under the influence of quantizing magnetic fields. We find that the dispersion and attenuation of phonons show striking oscillatory behaviors as varying the magnetic field at low temperatures. These oscillations are distinct when the Fermi energy is in different energy regimes. Moreover, the van Hove singularity of the Weyl spectrum can manifest as a transition between different oscillation patterns when increasing the magnetic field. These phonon behaviors could provide testable fingerprints of the Fermi surface morphology and relativistic feature of the Weyl semimetal.