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≥2 in the layered frustrated system and could offer a general approach to manipulate 3D stringlike topological objects for spintronic functions.
@article{arxiv.2205.09258,
title = {Bifurcation of a Topological Skyrmion String},
author = {Jing Xia and Xichao Zhang and Oleg A. Tretiakov and Hung T. Diep and Jinbo Yang and Guoping Zhao and Motohiko Ezawa and Yan Zhou and Xiaoxi Liu},
journal= {arXiv preprint arXiv:2205.09258},
year = {2022}
}