Abstract
A microscopic understanding of hydrodynamic transport in Dirac and Weyl semimetals has remained elusive in theoretical descriptions and experimental measurements. We investigate the structure and microscopic properties of transport in , a type-II Weyl semimetal exhibiting hydrodynamic transport. Here, we characterize the nature of the microscopic properties of as a function of temperature through ab initio calculations of the relevant scattering processes, including electron-phonon and electron-electron lifetimes, and provide equivalent calculations for copper as a point of reference. Additionally, we present an approach to calculate phonon drag, a mechanism invoked in recent experiments, through predictions of a phonon-mediated electron-electron lifetime. We show that the resistivity is very well described by the electron-phonon interaction alone, indicating exhibits conventional metallic electrical behavior in which strong electron-electron correlations do not play a significant role. After establishing the zone-averaged behavior of the calculated lifetimes, we further investigate specific features of the spatial distribution of the electron-phonon lifetime across the Fermi surfaces of to study possible scattering channels involved in hydrodynamic transport and quantify the degree of lifetime anisotropy in electron and hole pockets. This description of microscopic dynamics in prompts additional investigation of specific scattering channels and indicates the importance of phonon interactions in understanding connections between transport in hydrodynamic materials and strongly correlated systems including unconventional metals.
- Received 4 June 2018
- Revised 31 July 2018
DOI:https://doi.org/10.1103/PhysRevB.98.115130
©2018 American Physical Society