Electronic structure and spin polarization of ${\mathrm{Mn}}_x{\mathrm{Ga}}_{1-x}\mathrm{N}$

We present ab initio pseudopotential–density-functional calculations for the electronic structure of the dilute magnetic semiconductor ${\mathrm{Mn}}_x{\mathrm{Ga}}_{1-x}\mathrm{N},$ with a realistic $x=0.063,$ in its ordered ferromagnetic phase. We find that the introduction of Mn results in the formation of a 100% spin polarized $\sim 1.5\hspace{0.5em}\mathrm{eV}$-wide impurity band, primarily due to hybridization of Mn $3d$ and N $2p$ orbitals. This band renders the material half metallic and supports effective-mass transport within it. As such, ${\mathrm{Mn}}_x{\mathrm{Ga}}_{1-x}\mathrm{N}$ is a highly suitable material for spin injectors. Coupled with the previously reported high Curie temperature and inherent compatibility with GaN technology of this material, it emerges as a serious candidate for the next generation of spintronic devices.