2016/11/30 by Dominik Gresch, QuanSheng Wu, Georg W. Winkler +3
Materials Science · Physics and Astronomy · #2D Materials and Applications #Anisotropy #Field (mathematics) #Iron-based superconductors research #Magnetic field #Magnetoresistance #Paramagnetism #Symmetry (geometry) #Topological Materials and Phenomena #Zeeman effect #cond-mat.mes-hall #cond-mat.mtrl-sci
paper · pdf · doi:10.1088/1367-2630/aa5de7
published as New Journal of Physics 19 (3), 035001 (2017) (invited issue)
openalex created_date 2016/11/30 · arxiv created 2017/01/19 · openalex publication_date 2017/02/02 · arxiv updated 2017/08/31 · openalex updated_date 2026/08/06
The transition metal dipnictides TaAs 2 , TaSb 2 , NbAs 2 and NbSb 2 have recently sparked interest for exhibiting giant magnetoresistance. While the exact nature of the magnetoresistance in these materials is still under active investigation, there are experimental results indicating that it is of the anisotropic negative variety. We study the effect of magnetic fields on the band structure topology of these materials by applying Zeeman splitting. In the absence of a magnetic field, we find that the materials are weak topological insulators, which is in agreement with previous studies. When the magnetic field is applied, we find that type-II Weyl points form. This result is found first from a symmetry argument, and then numerically for a model of TaAs 2 and a tight-binding model of NbSb 2 . This effect could be of help in the search for an explanation of the anomalous magnetoresistance in these materials.