  Voltage-induced motion of a magnetic domain wall (DW) has potential in
developing novel devices with ultralow dissipation. However, the speed for the
voltage-induced DW motion (VIDWM) in a single ferromagnetic layer is usually
very low. In this work, we proposed VIDWM with high speed in a synthetic
antiferromaget (SAF). The velocity for the coupled DWs in the SAF is
significantly higher than its counterpart in a single ferromagnetic layer.
Strong interlayer antiferromagnetic exchange coupling plays a critical role for
the high DW velocity since it inhibits the tilting of DW plane with strong
Dzyaloshinskii-Moriya interaction. On the other hand, the Walker breakdown of
DW motion is also inhibited due to the stabilization of moment orientation
under a strong interlayer antiferromagnetic coupling. In theory, the
voltage-induced gradient of magnetic anisotropy is proved to be equal to an
effective magnetic field that drives DW.
