Vladyslav M. Kuchkin1,2, Pavel F. Bessarab3,4, Nikolai S. Kiselev1
1 PGI-1 and IAS-1 Forschungszentrum Jülich and JARA, Jülich, Germany
2 Department of Physics, RWTH Aachen University, Aachen, Germany
3 Science Institute of the University of Iceland, Reykjavík, Iceland
4 School of Science and Technology, Örebro University, Örebro, Sweden
Chiral magnets is a class of magnetic materials with competing exchange and Dzyaloshinskii-Moria interactions, which gives rise to the formation of a large variety of stable localized solutions – skyrmions [1]. The problem of controllable generation of skyrmions plays a key role in the future development of skyrmion applications. While the thermal generation of axially symmetric π-skyrmions is well established (Fig.1a), the approaches to obtaining skyrmions of other types are still unexplored. My talk is based on our recent publication [2] is aimed to glimpse a light on the mechanism of chiral droplet soliton nucleation (Fig.2b). The method we found allows selectively changing the nucleation probability of either chiral droplets or π-skyrmions by changing the tilt of the external magnetic field in the presence of small thermal fluctuations. Our findings are supported by the stochastic LLG and Monte-Carlo simulations and the harmonic transition state theory calculations.
Fig.1 (a) illustrates the case of perpendicular magnetic field, and (b) corresponds to the tilted magnetic field. The top row of images represents the snapshots of the system at different temperatures taken at thermal equilibrium. Each image in the bottom row corresponds to the top image after cooling at zero temperature.
References
[1] V. M. Kuchkin et al. Phys. Rev. B 102, 144422 (2020)
[2] V. M. Kuchkin et al. Phys. Rev. B 105, 184403 (2022)