Large enhancement of interlayer chiral coupling in sub-micron-scale magnetic tunnel junctions

Abstract We have investigated the interlayer chiral coupling (ICC) phenomenon, which occurs via the interlayer Dzyaloshinskii–Moriya interaction, in a ferromagnet/non-magnet/ferromagnet tri-layer structure using sub-micron-sized magnetic tunnel junctions. The tri-layer films were fabricated into sub-micron lateral size tunnel junctions, which exhibited an order of magnitude enhancement of the ICC-induced effective field compared to larger films. Moreover, the magnitude and even the sign of the effective field was observed to vary between devices, indicating that polycrystallinity plays an important role in ICC. We also demonstrate ICC-mediated in-plane magnetization switching induced by out-of-plane magnetic fields.