  In this letter, we have studied the spin torque based magnetization
oscillations and switching in presence of Rashba - Zeeman (RZ), Ruderman -
Kittel - Kasuya - Yoside (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.
