p-orbital half-metallicity in metal-free AsN2 monolayer with robust ferromagnetism

Two-dimensional (2D) metal-free half-metals, the embodiment of abundance ability and intrinsic completely spin-polarization, have attracted increasing interest in the fields of both scientific and technological aspects recently. Based on first-principles, we demonstrate that the metal-free honeycomb lattice of stoichiometry AsN2 exhibits unique electronic structure that results in the complete polarization of p-orbitals at the Fermi level, leading to intrinsic half-metallic behavior. In addition, the AsN2-based spin valve is evaluated by quantum transport simulations, which shows 100% magnetoresistance. Moreover, we find that this ferromagnetism is robust against various perturbations, including strain, carrier doping, electric field, and substrate. These findings provide important foundation for the future spintronics investigations and applications.