Ferromagnetic Type-II Weyl Semimetal in Pyrite Chromium Dioxide

Abstract

Magnetic topological materials have recently drawn significant importance and interest, due to their topologically nontrivial electronic structure within spontaneous magnetic moments and band inversion. Based on first-principles calculations, we propose that chromium dioxide, in its ferromagnetic pyrite structure, can realize one pair of type-II Weyl points between the $N$th and $(N+1)$th bands, where $N$ is the total number of valence electrons per unit cell. Other Weyl points between the $(N-1)$th and $N$th bands also appear close to the Fermi level due to the complex topological electronic band structure. The symmetry analysis elucidates that the Weyl points arise from a triply-degenerate point splitting due to the mirror reflection symmetry broken in the presence of spin-orbital coupling, which is equivalent to an applied magnetic field along the direction of magnetization. The Weyl points located on the magnetic axis are protected by the three-fold rotational symmetry. The corresponding Fermi arcs projected on both (001) and (110) surfaces are calculated as well and observed clearly. This finding opens a wide range of possible experimental realizations of type-II Weyl fermions in a system with time-reversal breaking.

8 pages, 5 figures

References in corpus (13)

• WannierTools: An open-source software package for novel topological materials
• Topological quantum chemistry
• Weyl semimetal phase in non-centrosymmetric transition metal monophosphides
• Wannier representation of Z_2 topological insulators
• Z2Pack: Numerical Implementation of Hybrid Wannier Centers for Identifying Topological Materials
• Anomalous Hall Effect in Weyl Metals
• Weyl Semimetals, Fermi Arcs and Chiral Anomalies (A Short Review)
• Classification of reflection symmetry protected topological semimetals and nodal superconductors
• Weyl semimetals from noncentrosymmetric topological insulators
• Topological Hopf and chain link semimetal states and their application to Co2MnGa (Theory and Materials Prediction)
• Topological Weyl and Node-Line Semimetals in Ferromagnetic Vanadium-Phosphorous-Oxide $\beta$-V${}_2$OPO${}_4$ Compound
• Heavy Weyl fermion state in CeRu${}_4$Sn${}_6$
• Strongly Ideal Robust Weyl Semimetals in Cubic Symmetry with Spatial-Inversion Breaking

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