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The 1-D nanoscale structures are studied with a potential relief containing magnetic barriers separated by nonmagnetic quantum wells in the absence of exchange interaction between the magnetic moments of adjacent barriers. The considered structure is the sequence of N barriers divided into two “ferromagnetic domains” of the length n and N - n -- 1, both having parallel internal fields. In contrast, the internal field of the nth barrier is not coplanar with respect to the internal fields of the left and/or right “domains.” The degree of spin polarization of an electron wave transmitted through this system is calculated with the assumption that the incident wave is unpolarized with the degree of its polarization equals zero. It is shown that the degree of polarization of the transmitted wave as a function of the impulse exhibits a sequence of sufficiently wide plateaus, which are close to unity. In particular, there are significant deviations from the known spintronics phenomena found earlier in this system such as the valve, filter, and giant magnetoresistance effects. This circumstance provides opportunities for managing the transport properties of the system by varying the noncoplanar degrees of freedom of the system. [ABSTRACT FROM AUTHOR]

In this paper, we investigate electronic transport through II-VI semiconductor resonant-tunneling structures containing diluted magnetic impurities. Due to the exchange interaction between the conduction electrons and the impurities, there arises a giant Zeeman splitting in the presence of a moderately low magnetic field. As a consequence, when the quantum well is magnetically doped, the current-voltage characteristics shows two peaks corresponding to transport for each spin channel. This behavior is experimentally observed and can be reproduced with a simple tunneling model. The model thus allows to analyze other configurations. First, we further increase the magnetic field, which leads to a spin polarization of the electronic current injected from the leads, thus giving rise to a relative change in the current amplitude. We demonstrate that the spin polarization in the emitter can be determined from such a change. Furthermore, in the case of an injector with magnetic impurities, our model shows a large increase in peak amplitude accompanied by a shift of the resonance to higher voltages with increasing fields. We find that this effect arises from a combination of 3-D incident distribution, giant Zeeman splitting, and broad resonance linewidth. [ABSTRACT FROM AUTHOR]