The DMI Mitre Gear: In-Plane Control of Perpendicular Interfacial Magnetization in Ta/NiFe Bilayers

The Dzyaloshinskii–Moriya interaction (DMI), which originates from spin–orbit coupling and broken inversion symmetry, plays a key role in chiral magnetic phenomena. In this talk, I will show that Ta/NiFe bilayers exhibit an antisymmetric planar Hall effect (APHE) that points to a small perpendicular interfacial magnetization generated by interfacial DMI and locked to the orientation of the in-plane magnetization.

To describe this effect, we introduce the concept of a DMI Mitre Gear, in which rotating the bulk in-plane magnetization produces an orthogonal interfacial magnetic response with a one-to-one angular relation. This framework captures the main experimental findings and highlights DMI as a mechanism for creating and controlling perpendicular interfacial magnetization.

This concept not only advances our understanding of interfacial chiral magnetism but also suggests new routes toward chirality-controlled, multistate spintronic devices, including possible applications in neuromorphic in-memory computing.