Dopant‐Induced Magnetism and Spin‐Dependent Electronic Transport in Black Arsenic Nanoribbons

Using first‐principles calculations, we investigate dopant‐induced magnetism in hydrogen‐passivated black arsenic nanoribbons. Light main‐group dopants induce spin splitting and local magnetic moments, while heavy dopants suppress magnetism. Band structure and density of states (DOS) analyses reveal a unified mechanism: the competition between localized and delocalized dopant‐induced p z impurity states governs exchange‐driven spin polarization. Light dopants form localized states near the Fermi level due to significant orbital energy mismatch with the host, thereby enhancing the DOS and promoting magnetism. In contrast, heavy dopants hybridize strongly with As p orbitals through better energy alignment, which quenches the magnetic moments. This mechanism is robust against edge geometry changes. Spin‐dependent transport reflects these magnetic states with edge‐dependent characteristics, offering insights into impurity‐driven magnetism and its modulation in group‐V nanostructures.