Phonon-induced magnetoresistivity of Weyl semimetal nanowires

Abstract

We study longitudinal magnetotransport in disorder-free cylindrical Weyl semimetal nanowires. Our theory includes a magnetic flux $Φ$ piercing the nanowire and captures the finite curvature of the Fermi arc in the surface Brillouin zone through a boundary angle $α$. 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 $α$ and to Aharonov-Bohm phases due to $Φ$. 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.