Discovery of Magnetic-Weyl Semimetallic Phase in a Doped Topological Crystalline Insulator

Materials that can host a magnetic-Weyl semimetallic phase represent a novel platform for fundamental physics studies and can also be potentially applicable for quantum computing. The search for such magnetic-Weyl semimetals is ongoing given the recent discovery of Weyl semimetals which show absence of time reversal or inversion symmetry [1, 2]. In our study, we demonstrate a new pathway to engineer magnetic Weyl semimetals by doping topological crystalline insulators (TCI) such as SnTe with a magnetic transition metal element, such as Cr. The magnetic dopant breaks both time reversal and inversion symmetry while maintaining the band inversion between Sn-p and Te-p orbitals, thus resulting in Weyl nodes in the bulk. These Weyl nodes were characterized through chirality calculation, large intrinsic anamolous Hall conductivity (AHC), and presence of Fermi arcs in the surface. Furthermore, the Weyl semimetallic phase is maintained even under dilute dopant concentrations, suggesting experimental feasibility of realizing this system.
[1] M. Z. Hassan et al, Annu. Rev. Condens. Matter. Phys. 8, 289 (2017).
[2] Z. Wang et al, Phys. Rev. Lett. 117, 236401 (2016).