Interlayer coupling in (In,Mn)As/InAs/(In,Mn)As magnetic semiconductor trilayer structures

p- (In,Mn)As /n- InAs /p- (In,Mn)As trilayer structures have been prepared by molecular beam epitaxy on GaSb/GaAs/GaAs(001) substrates. Ferromagnetic coupling has been found between the two magnetic p-(In,Mn)As layers with a rather thick n-InAs layer (d∼30 nm). The magnitude of the ferromagnetic coupling is estimated to be J=7.6×10−3 mJ/m2, being one order of magnitude larger than that extracted for the (Ga,Mn)As-based trilayer structures [D. Chiba et al., Appl. Phys. Lett. 77, 1873 (2000)].