Transport properties and origin of ferromagnetism in (Ga,Mn)As

Magnetotransport properties of p-type ferromagnetic (Ga, Mn) As, a diluted magnetic semiconductor based on III-V semiconductors, are measured and the p-d exchange between holes and Mn 3d spins is determined. The ferromagnetic transition temperatures calculated based on the Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction using the exchange reproduce remarkably well the observed ferromagnetic transition temperatures, demonstrating that ferromagnetism of (Ga, Mn) As has its origin in the RKKY interaction mediated by holes.