Effect of electron-phonon scattering on the electronic transport of Weyl semimetal ${\mathrm{WP}}_2$

Although the topological properties of type-II Weyl semimetal ${\mathrm{WP}}_2$ have been widely studied by both the experiments and the theoretical calculations, the dominant electron-phonon scattering and the effect of Fermi pockets on the electronic transport still remain elusive. In this work, we investigate the electronic transport of Weyl semimetal ${\mathrm{WP}}_2$ by the first-principles calculations and semiclassical transport theory. The results well reproduce the resistivity from the experiments. Carriers in the Fermi pockets favor much less scattering rates. Holes are found to possess much lower scattering rates than electrons at low temperatures, while both types of carriers have close scattering rates at high temperatures. At low temperatures, the scattering rates are mainly contributed by the acoustic modes, especially the transverse acoustic mode, while the rates at high temperatures are jointly contributed by acoustic modes and low-frequency optical modes, especially $B_2^{\left(1\right)}$ and $B_1^{\left(2\right)}$. Compared to other modes, the $A_1$ modes are found to possess larger linewidths and exhibit significant chemical potential dependent behaviors. The low-temperature resistivity is found to increase monotonously as the chemical potential increases. Moreover, both the carrier density and the resistivity can be well tuned by applying the uniaxial or volume strains. The carrier density is enhanced under the tensile strains along the $a$ and $c$ axes, which leads to the decreasing resistivity. In contrast, the tensile strain along the $b$ axis suppresses the carrier density and thus increases the resistivity. The behaviors of carrier density and resistivity can be attributed to the shift of Fermi pockets and the variation of electron-phonon coupling strength under the strains.