Frustrated Skyrmions and Bimerons

Skyrmions and bimerons are typical topological spin textures that can be stabilized in frustrated magnetic systems with competing exchange interactions [1]. They have multiple degrees of freedom, which could be manipulated by external driving forces and thus, may lead to novel applications, such as the helicity-based information processing in nanoscale devices. Therefore, it is important to understand the fundamental physical properties of frustrated skyrmions and bimerons, and to explore their potential applications.In this talk, I will first briefly introduce topological spin textures in magnetic systems [2]. I will then talk about the static and dynamic properties of isolated skyrmions and bimerons in a magnetic monolayer with frustrated exchange interactions [3]. I will focus on the discussion of the dynamic behaviors of isolated skyrmions and bimerons driven by spin torques, including linear motion, elliptical motion, and rotation. Besides, I will discuss the current-induced dynamics of a three-dimensional skyrmion string in a frustrated multilayer system [4]. Finally, at the end of the talk, I will share some views on possible future directions for the study of topological spin textures, which are not limited to the frustrated magnetic systems.

Acknowledgments

This work was done in collaboration with J. Xia, O. A. Tretiakov, H. T. Diep, L. Shen, Z. Hou, W. Wang, J. Yang, G. P. Zhao, M. Ezawa, Y. Zhou, and X. Liu. This work was supported by JSPS KAKENHI (Grant No. JP20F20363).

Figure 1. Different types of two-dimensional (2D) and three-dimensional (3D) topological spin textures, including skyrmion, bimeron, skyrmionium, bimeronium, skyrmion string, bimeron string, and bifurcated skyrmion string.

References:

[1] Nat. Commun. 6, 8275 (2015); Phys. Rev. B 93, 064430 (2016); Nat. Commun. 8, 14394 (2017).

[2] J. Phys. Condens. Matter 32, 143001 (2020).

[3] Nat. Commun. 8, 1717 (2017); Phys. Rev. B 101, 144435 (2020).

[4] Phys. Rev. B 105, 214402 (2022).