Regensburg 2016 – scientific programme
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TT: Fachverband Tiefe Temperaturen
TT 24: Transport: Weyl Semimetals
TT 24.5: Talk
Tuesday, March 8, 2016, 10:45–11:00, H18
Bulk Fermi Surface Topology of the Weyl Semimetal Tantalumarsenide — •Marcel Naumann1, Frank Arnold1, Shu-Chun Wu1, Yan Sun1, Marcus Peter Schmidt1, Horst Borrmann1, Claudia Felser1, Binghai Yan1,2, and Elena Hassinger1 — 1Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany — 2Max Planck Institute for Physics of Complex Systems, 01187 Dresden, Germany
Tantalumarsenide is a member of the non-centrosymmetric monopnictides which are putative Weyl semimetals. We have reconstructed the Fermi surface topology of TaAs by angular dependent Shubnikov-de Haas and de Haas-van Alphen measurements of a high quality single crystal and ab initio density-functional theory bandstructure calculations. By fitting the experimental angular dependence of the quantum oscillation frequencies to the calculated DFT bandstructure, we were able to reconstruct the entire Fermi surface and identify individual electron and hole pocket orbits in our measurements. We find that the Fermi surface consists of eight distinct pockets along each nodal ring, three pairs of topologically non-trivial electron Weyl-pockets and two trivial hole-pockets. Their effective charge carrier masses and scattering times have been determined by temperature and magnetic field dependencies of the quantum oscillation amplitude. Unlike the other members of the non-centrosymmetric monopnictides, TaAs is the first Weyl metal candidate were the Fermi energy is sufficiently close to both Weyl points to generate separate Weyl pockets with different chiralities.