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

Abstract

Employing the first-principles combined with hybrid functional calculations, the electronic and magnetic properties of GaAs doped with a N 2 molecule are investigated in this work. We find that in Ga 32 As 31 (N 2) As the N-N split is able to saturate the dangling bond of Ga atom,form sp 3 -like hybridization, and simultaneously supply an extra localized electron, leading to a magnetic ground state with a magnetic moment of ∼1μ B. 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 Ga 32 As 31 (N 2) As alloy decreases, which is relative to GaAs. Finally we discuss and explain why the magnetism is not discovered in previous experiments and theories.