Spin polarization and spin-dependent transmittance in II-VI diluted magnetic semiconductor heterostructure

In this work, we carried out detailed investigation of a Cd 1-xMnxTe/CdTe/Cd1-xMnxTe diluted magnetic semiconductor based quantum well. Our theoretical results are based on an accurate self-consistent resolution of the one-dimension Schrdinger and Poisson's equations in the framework of the mean-field approximation for spin-up and spin-down orientations of carriers coupled via the spd exchange interaction. From the calculation of spin-dependent carrier densities for ferromagnetic and anti-ferromagnetic coupling, we evidence the spin-up and spin-down space separation for holes in quantum well for different values of band offsets. From deduced spin polarizations, we show that the CdTe region acts as a layer of spin rearrangement and spin reversal, respectively, in the ferromagnetic and anti-ferromagnetic coupling. The transmittance coefficients T+ and T- of injected spin-up and spin-down carriers are evaluated as a preliminary work to assess the spin-dependent currents in devices consisting of alternatively layers of non-magnetic and diluted magnetic semiconductors. © 2010 Elsevier B.V.