In this paper, we study the domain wall motion induced by vertical current flow in asymmetric magnetic tunnel junctions. The domain wall motion in the free layer is mainly dictated by the current-induced field-like torque acting on it. We show that as we increase the MTJ asymmetry, by considering dissimilar ferromagnetic contacts, a linear-in-voltage field-like torque behavior is accompanied by an enhancement in the domain wall displacement efficiency and a higher degree of bidirectional propagation. Our analysis is based on a combination of a quantum transport model and magnetization dynamics as described by the Landau–Lifshitz–Gilbert equation, along with comparison to the intrinsic characteristics of a benchmark in-plane current injection domain wall device.
Bibliographical noteFunding Information:
DS, TL, and JPW were partially supported by DARPA ERI FRANC program, United States . We acknowledge useful discussions with D.E. Nikonov from Intel Corporation. The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
DS, TL, and JPW were partially supported by DARPA ERI FRANC program, United States . We acknowledge useful discussions with D.E. Nikonov from Intel Corporation.
- Domain wall
- Magnetic tunnel junctions
- Spin transfer torque