Spin torque oscillator and magnetization switching in double-barrier Rashba Zeeman magnetic tunnel junction

Abstract

In this work, we have studied the spin torque based magnetization oscillations and switching in presence of Rashba–Zeeman (RZ), Ruderman–Kittel–Kasuya–Yosida (RKKY) and Dzyaloshinskii–Moriya (DM) interactions in a double-barrier RZ|Heavy Metal (HM)|RZ magnetic tunnel junction (MTJ). The system has stable magnetization oscillations and can work as an oscillator or a switcher for a significant difference in the strength of RKKY and DM interaction under suitable spin transfer torque (STT). For the proposed system with same order of RKKY and DM interaction, a nonlinear characteristic of the magnetization oscillation is observed. However, this nonlinearity of oscillations can be reduced by an external magnetic field or considering a material with suitable RZ interaction. In addition to this, our study reveals the magnetization switching can be tuned by using suitable STT. A dependence of switching time on layer thickness is also observed. Also, the switching speed increases with the thickness for systems having either same order of RKKY and DM interaction or dominated by RKKY interaction. An opposite characteristic is seen when DM interaction dominates over RKKY interaction.