Electronic and magnetic properties of N-N split substitution in GaAs: A hybrid density functional study

Employing the first-principles combined with hybrid functional calculations, the electronic and magnetic properties of GaAs doped with a N2 molecule are investigated in this work. We find that in Ga32As31(N2)As the N-N split is able to saturate the dangling bond of Ga atom ,form sp3-like hybridization, and simultaneously supply an extra localized electron, leading to a magnetic ground state with a magnetic moment of ∼1μB. This magnetic ground state is different from previously nonmagnetic results predicted by PBE functional, which results from the self-interaction error inherent in semi-local density functional theory. Moreover, the band gap of magnetic ground state of Ga32As31(N2)As alloy decreases, which is relative to GaAs . Finally we discuss and explain why the magnetism is not discovered in previous experiments and theories.