Attractively interacting skyrmions under magneto-crystalline anisotropy in 2D chiral magnets

Magnetic skyrmions, topologically protected nanometric swirling spin configurations, are potentially capable of carrying information in magnetic memories and computing devices [1]. To enhance device controllability, it would be important to control inter-skyrmion interactions. Recently, attractive inter-skyrmion couplings are found to appear due to a frustrated exchange coupling [2] and due to the three-dimensional magnetic configurations [3, 4]. On the other hand, the inter-skyrmion interaction in two-dimensional chiral magnets was believed to be repulsive. This is true for two circular skyrmions. However, in this study, we find that deformation of skyrmion shape can change the sign of the interaction, giving rise to the inter-skyrmion attractions. We analytically derive an approximated inter-skyrmion interaction, V_app(R), at distance R and numerically investigate the inter-skyrmion interaction, V(R), under a magneto-crystalline anisotropy [5].

References

[1] N. Nagaosa and Y. Tokura, Nat. Nanotechnol. 8, 899 (2013). [2] L. Rózsa, A. Deák, E. Simon, R. Yanes, et al., Phys. Rev. Lett. 117, 157205 (2016). [3] C. Loudon, A. O. Leonov, A. N. Bogdanov, M. C. Hatnean, et al., Phys. Rev. B 97, 134403 (2018). [4] H. Du, X. Zhao, F. N. Rybakov, A. B. Borisov, et al., Phys. Rev. Lett. 120, 197203 (2018). [5] M. Kameda, R. Koyama, T. Nakajima, and Y. Kawaguchi, Phys. Rev. B 104, 174446 (2021).