Magnetic properties in III-V diluted magnetic semiconductor quantum wells

Spin injection in low-dimensional semiconductors have a great potential to be used in magnetoelectronics and spintronics. In our work we analyze the electronic properties of the hole gas formed in Ga1−xMnxAs/GaAs/Ga1−xMnxAs heterostructures. We find that there is an RKKY-type exchange coupling between the magnetic layers that oscillates between ferromagnetic and antiferromagnetic as a function of the different parameters of the problem. As an example we calculate the spin-dependent hole density, the polarization and the coupling energy, using an efficient self-consistent procedure to solve simultaneously the Schrödinger and Poisson equations, taking into account the interaction with Mn magnetic moments. Our results indicate that the coupling energy also oscillates in terms of the band offset Vw which describes the difference in electronegativity between the Mn and GaAs atoms.