Carrier screening and transport in novel chiral 3D Dirac materials

From QCLab
  • Speaker: Hwang, Euyheon (Sungkyungkwan University)
  • Date: Wednesday October 14, 2015 17:00
  • Place: Jeongho Seminar Room

Following the very extensive research activity in graphene over the last ten years, a great deal of interest in condensed matter physics has focused on other 2D and 3D Dirac materials where the elementary low energy noninteracting electronic energy dispersion is linear. We introduce the new 3D Dirac materials and present the density and temperature-dependent carrier conductivity in chiral 3D Dirac materials focusing on resistive scattering from screened Coulomb disorder due to random charged impurities. The scaling properties describing how the conductivity depends on the density and temperature can be used to establish the Dirac nature of 3D systems through transport measurements. We also theoretically calculate and compare the single-particle relaxation time \tau_s, defining the quantum level broadening, and the transport scattering time \tau_t, defining the conductivity, in the presence of screened charged impurity scattering. Finally, we present the dependence of the conductivity on carrier density and temperature for arbitrary chiral band dispersion in arbitrary dimensionality. We establish that the temperature and the density dependence of the conductivity manifests scaling behaviors determining, respectively, the intrinsic semimetallic or the extrinsic metallic property of the gapless system.