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arXiv · 2212.02342

Skyrmion inertia in synthetic antiferromagnets

Sujit Panigrahy·Sougata Mallick·Joao Sampaio·Stanislas Rohart
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Abstract

We describe the dynamics of magnetic skyrmions in synthetic antiferromagnets (SAF), with a finite interlayer coupling. Due to the opposite gyrovector of the skyrmions in the two SAF layers, the coupled skyrmions reach a stationary regime with a spatial separation, in a direction orthogonal to their velocity. As a consequence, and contrary to the ferromagnetic situation, a transient regime necessarily occurs, with a finite acceleration, related to an inertia, and that limits its time response. The formalism developed here, based on two coupled Thiele equations, allows a quantitative description of this phenomenon. The time constant associated to the transient regime scales inversely with the antiferromagnetic coupling constant. We also show that the coupling force reaches a maximal value at a finite skyrmion separation. This sets a maximum velocity limit, beyond which the the coupling force cannot stabilize the bound state.

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Sujit Panigrahy, Sougata Mallick, Joao Sampaio, Stanislas Rohart. 2022-12-05. Skyrmion inertia in synthetic antiferromagnets. https://doi.org/10.1103/physrevb.106.144405

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