Knitting mechanism of skyrmions from interfacial magnetic anisotropies in γ-FeMn/Co bilayer films

Interfacial skyrmions, which hold great promise for applications among various types of skyrmions, typically form through interfacial Dzyaloshinskii–Moriya interactions (DMI) induced by heavy metal layers. In contrast to conventional interfacial DMI, we propose an interfacial skyrmion knitting mechanism stemming from 3Q-antiferromagnet/ferromagnet interfacial interactions, with micromagnetic simulations confirming its feasibility. Our experimental investigations on the effects of critical temperature, magnetic anisotropy, and interface morphology on the topological Hall effect in γ-FeMn/Co bilayer films yield results consistent with this proposed knitting mechanism. Micromagnetic simulations further reveal the potential of this mechanism to generate diverse complex topological spin textures via artificially engineered interface morphologies. Our work enriches skyrmion formation mechanisms and material systems, broadening the platform for skyrmionics research.