Antiferromagnetic exchange coupling between GaMnAs layers separated by a nonmagnetic GaAs:Be spacer

Abstract

Interlayer exchange coupling (IEC) between two Ga0.95Mn0.05As layers separated by Be-doped GaAs spacers was investigated using magnetometry and neutron scattering measurements, which indicated the presence of robust antiferromagnetic IEC under certain conditions. We argue that the observed behavior arises from a competition between the IEC field and magnetocrystalline anisotropy fields intrinsic to GaMnAs layers. We estimate the magnitude of the IEC field and show how it decays with increasing temperature.