Phonon-induced magnetoresistivity of Weyl semimetal nanowires

TL;DR

This paper investigates how phonon interactions affect magnetoresistivity in Weyl semimetal nanowires, revealing surface state dominance and abrupt resistivity changes linked to Fermi point configurations and magnetic flux.

Contribution

It introduces a theoretical framework for phonon-induced resistivity in Weyl nanowires considering surface states, magnetic flux, and Fermi arc curvature, highlighting the impact of Fermi point pairs on resistivity.

Findings

Surface states dominate low-energy transport.

Resistivity is highly sensitive to magnetic flux and Fermi arc curvature.

Transitions between Fermi point configurations cause abrupt resistivity changes.

Abstract

We study longitudinal magnetotransport in disorder-free cylindrical Weyl semimetal nanowires. Our theory includes a magnetic flux $\Phi$ piercing the nanowire and captures the finite curvature of the Fermi arc in the surface Brillouin zone through a boundary angle $\alpha$. Electron backscattering by acoustic phonons via the deformation potential causes a finite resistivity which we evaluate by means of the semiclassical Boltzmann approach. We find that low-energy transport is dominated by surface states, where transport observables are highly sensitive to the angle $\alpha$ and to Aharonov-Bohm phases due to $\Phi$. A generic subband dispersion relation allows for either one or two pairs of Fermi points. In the latter case, intra-node backscattering is possible and implies a parametrically larger resistivity than for a single Fermi point pair. As a consequence, large and abrupt resistivity changes take place across the transition points separating parameter regions with a different number of Fermi point pairs in a given subband.