Spin-Current Oscillations in Diluted Magnetic Semiconductor Multibarrier GaMnAs/GaAs: Role of Temperature and Bias Voltage

Abstract

This paper has studied the electronic properties of multi-diluted magnetic semiconductor (DMS) layers Ga(1-x)MnxAs interposed between nonmagnetic GaAs layers. The asymmetry of confining potential on the transmission coefficient by tuning the temperature and the size of the (DMS) layers was discussed. The diluted magnetic layers Ga(1-x)MnxAs behave as barriers for spin-up holes and quantum wells for spin-down holes. Furthermore, we have addressed the impact of an applied bias voltage and the temperature on the variation of the spin-polarization and spin current densities. Our findings reveal that the transmission coefficients present an oscillating behavior due to the resonant states and strongly depend on the temperature of the system and the number of magnetic layers. Furthermore, the obtained results demonstrated that the number of these states is multiplied by augmenting the magnetic layers. Moreover, we demonstrate that the asymmetric structure presents a completely different transmission of holes than the symmetric structure. Furthermore, the negative differential resistance (NDR) is demonstrated in the current density variations. Especially, this (NDR) was more intense for spin-up holes than spin-down holes. The findings in the present paper can be useful in manufacturing spin-filters by adjusting the values of the temperature and the external voltages.

Spin-current in a Magnetic Semiconductor Tunnel Junction: Effect of External Bias Voltage

“…This expression is valid in systems with Hamiltonians containing up to second-order terms in the momentum operator [10] and is so far considered as the canonical definition for spin currents. Nevertheless, the study of the spin-current profile remains quite limited and is only performed in effective models where the wave functions are relatively simple [11][12][13][14].…”