Electron and spin dynamics in Dirac semimetals from first principles

Bulk Dirac semimetals such as Na3Bi and Cd2As3 have received attention due to their non-trivial band structure topology and the novel physics associated with it, including anomalous transport regimes and protected surface Fermi arcs. At present, first-principles studies of the scattering mechanisms and charge transport properties of Dirac semimetals remain limited. In this talk, we will present first-principles calculations of the electron mobility (and its governing scattering mechanisms), magneto-transport and spin relaxation times in selected Dirac semimetals. These studies employ the PERTURBO code developed in our group to efficiently compute electron scattering mechanisms and solve the Boltzmann transport equation. We overcome key challenges associated with Dirac semimetals, including calculating electron-phonon scattering processes near the Dirac cones using effective interpolation techniques, correctly treating spin-orbit coupling, and handling materials with large unit cells. Our results attempt to clarify the microscopic origin of the large mobilities and magnetoresistance of topological semimetals, and characterize their spin dynamics, for which few experimental results or theoretical predictions exist.