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arXiv · 2205.09258

Bifurcation of a Topological Skyrmion String

Jing Xia·Xichao Zhang·Oleg A. Tretiakov·Hung T. Diep·Jinbo Yang·Guoping Zhao·Motohiko Ezawa·Yan Zhou·Xiaoxi Liu
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Abstract

Manipulation of three-dimensional (3D) topological objects is of both fundamental interest and practical importance in many branches of physics. Here, we show by spin dynamics simulations that the bifurcation of a 3D skyrmion string in a layered frustrated system could be induced by the dampinglike spin-orbit torque. The bifurcation of a skyrmion string happens when the skyrmion string carries a minimal topological charge of $Q=2$. We demonstrate that three types of bifurcations could be realized by applying different current injection geometries, which lead to the transformation from I-shaped skyrmion strings to Y-, X-, and O-shaped ones. Besides, different branches of a bifurcated skyrmion string may merge into an isolated skyrmion string spontaneously. The mechanism of bifurcation should be universal to any skyrmion strings with $Q\geq 2$ in the layered frustrated system and could offer a general approach to manipulate 3D stringlike topological objects for spintronic functions.

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Jing Xia, Xichao Zhang, Oleg A. Tretiakov, Hung T. Diep, Jinbo Yang, Guoping Zhao, Motohiko Ezawa, Yan Zhou, Xiaoxi Liu. 2022-05-19. Bifurcation of a Topological Skyrmion String. https://doi.org/10.1103/physrevb.105.214402

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