First-principles studies of interlayer exchange coupling in (Ga, Mn)As-based diluted magnetic semiconductor multilayers

Interlayer exchange coupling (IEC) in a series model diluted magnetic semiconductor multilayers consisting of two magnetic (Ga, Mn)As layers separated by nondoped or Be-doped GaAs nonmagnetic spacers is studied by first-principles calculations. For the GaAs spacers without Be doping, the IEC is always ferromagnetic and is well described by the Ruderman-Kittle-Kasuya-Yoshida interaction based on a two-band model for a gaped system. For the Be-doped GaAs spacers, the IEC is found to be tunable and the antiferromagnetic IEC is achieved via Be-doping in the interfaces between the (Ga, Mn)As layers and the spacers.