MnNBr Monolayer: A High‐Temperature Ferromagnetic Half‐Metal with Type‐II Weyl Fermions

Abstract

2D ferromagnetic materials with full spin polarization, high Curie temperature, and novel massless fermions are highly desirable for spintronics applications. In article number 2100115, Zhifeng Liu and co-workers demonstrate that the orthorhombic MnNBr monolayer is a needed ferromagnetic half-metal, which not only has a high Curie temperature (910 K), but also holds a type-II Weyl state with Lorentz symmetry broken. Remarkably, near the type-II Weyl point, there is direction-dependent band dispersion: the largest fermion velocities up to 6.86 × 105 m s−1 and quasi-flat bands with negligible band dispersion can be found in different k directions.