Influence of anisotropy, tilt and pairing of Weyl nodes: the Weyl semimetals TaAs, TaP, NbAs and NbP★
Dept. of Physics, University of Rome Tor Vergata,
via della Ricerca Scientifica 1,
2 Istituto Nazionale di Fisica Nucleare (INFN), Tor Vergata, Italy
3 Université Aix-Marseille, Laboratoire de Physique des Interactions Ioniques et Moléculaires (PIIM), UMR CNRS 7345, 13397 Marseille, France
4 Institut für Festkörpertheorie und -optik, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena, Germany
a e-mail: email@example.com
b Present address: Theory and Simulation of Materials (THEOS), École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland.
Received in final form: 15 June 2020
Published online: 17 August 2020
By means of ab initio band structure methods and model Hamiltonians we investigate the electronic, spin and topological properties of four monopnictides crystallizing in bct structure. We show that the Weyl bands around a WP W1 or W2 possess a strong anisotropy and tilt of the accompanying Dirac cones. These effects are larger for W2 nodes than for W1 ones. The node tilts and positions in energy space significantly influence the DOS of single-particle Weyl excitations. The node anisotropies destroy the conventional picture of (anti)parallel spin and wave vector of a Weyl fermion. This also holds for the Berry curvature around a node, while the monopole charges are independent as integrated quantities. The pairing of the nodes strongly modifies the spin texture and the Berry curvature for wave vectors in between the two nodes. Spin components may change their orientation. Integrals over planes perpendicular to the connection line yield finite Zak phases and winding numbers for planes between the two nodes, thereby indicating the topological character.
Key words: Solid State and Materials
Supplementary material in the form of one pdf file available from the Journal web page at https://doi.org/10.1140/epjb/e2020-10110-x.
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