Oscillatory tunneling magnetoresistance in Fe3O4/GaAs/Fe3O4 junction

Spintronics strives to revolutionize conventional electronics by integrating magnetic materials with semiconductor devices, such as the spin field effect transistor (SFET), which not only improve the capabilities of electronic devices, but develop new functionalities. For electrodes of spin injection and detection in SFET device, half metallic Fe₃O₄ is an attractive candidate because its high Curie temperature of 858 K, large spin polarization near 100% at the Fermi level and relatively high electronic conductivity at room temperature, which is believed to benefit the injection of spin carriers into the semiconductors. For ferromagnetic metal(FM)/Semiconductor system, Fe₃O₄/GaAs is a very promising system for the fabrication of magnetoelectronic devices due to the Schottky contact of the Fe₃O₄/GaAs interface, which is crucial for studying the behaviors of spin dependent transportation for the devices. It is reported that in a FM/I/NM/I/FM double tunnel junction, where NM is the normal metal, and I the insulating barrier, theories predicted an oscillation of the tunneling magnetoresistance (TMR) effect as a function of the NM layer thickness because the spin polarization of the tunneling electron oscillates as a result of the resonant tunneling. Furthermore, Quantum oscillation of spin polarization in GaAs channel was experimentally demonstrated. In this paper, we have presented a theoretical approach to the tunneling conductance and TMR in a Fe₃O₄/GaAs/Fe₃O₄ magnetic double tunnel junction with both ballistic and diffusive components.