Modeling of Spin-Polarized Currents in Zinc Blende-based Magnetic Tunnel Junctions Featuring the Dresselhaus Effect
Fatimah A. Noor*, Hantika Mardianti, Gilang M. Kartiwa and Khairurrijal
Department of Physics, Physics of Electronic Materials Research Division,
Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung,
Jalan Ganesa 10, Bandung 40132, Indonesia
*Email: fatimah[at]fi.itb.ac.id
Abstract
In this study, the spin-polarized currents in a magnetic tunnel junction (MTJ) with a Fe/GaAs/Fe structure were calculated by considering the Dresselhaus effect. First, the transmittance was calculated using the Airy wave function approach, where it was found that the electron transmittance for each spin state is different and the incident angle affects electron transmittance and electron polarization. It was further shown that electron polarization is also affected by the electron energy and the barrier width, and that the electron transmittance is quasi-symmetric to the incident angle. The obtained transmittances were subsequently used to calculate the spin-polarized current in the MTJ, where it was found that the current density for both spin states increases with the addition of external voltage. It was also shown that the current density increases as the barrier width decreases. In addition, the temperature and the incident angle of the electrons affect the current density, where the maximum current density is obtained when the electrons come in a direction perpendicular to the barrier. We herein determined analytically that a high device performance of the MTJ could be achieved by simply controlling the device parameters of barrier width, temperature and incident angle of the electron.
Keywords: Dresselhaus term, Magnetic tunnel junction, Spin-polarized current, Transmittance, Zinc blende material
Topic: Optical, luminescence, Electronic Materials and applications