Thermal generation of droplet soliton in chiral magnet

• Main Authors: Kuchkin, Vladyslav, Bessarab, Pavel, Kiselev, Nikolai S.
• Other Authors: Raunvísindastofnun (HÍ), Science Institute (UI), Verkfræði- og náttúruvísindasvið (HÍ), School of Engineering and Natural Sciences (UI), Háskóli Íslands, University of Iceland
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Physical Society (APS) 2022
• Subjects: Dzyaloshinskii-Moriya interaction; Entropy; Ferromagnetism; Micromagnetism; Skyrmions; Spin dynamics; Spin texture; Iceland
• Online Access: https://hdl.handle.net/20.500.11815/3995; https://doi.org/10.1103/PhysRevB.105.184403

Controlled creation of localized magnetic textures beyond conventional π-skyrmions is an important problem in the field of magnetism. Here, by means of spin dynamics simulations, Monte Carlo simulations, and harmonic transition state theory we demonstrate that an elementary chiral magnetic soliton with zero topological charge—the chiral droplet—can be created by thermal fluctuations in the presence of the tilted magnetic field. The proposed protocol relies on an unusual kinetics combining the effects of the entropic stabilization and low-energy barrier for the nucleation of a topologically trivial state. Following this protocol by varying temperature and the tilt of the external magnetic field, one can selectively generate chiral droplets or π-skyrmions in a single system. The coexistence of two distinct magnetic solitons establishes a basis for a rich magnetization dynamics and opens up the possibility for the construction of more complex magnetic textures such as skyrmion bags and skyrmions with chiral kinks. Deutsche Forschungsgemeinschaft (DFG) through SPP 2137 "Skyrmionics" Grant No. KI 2078/1-1, the Russian Science Foundation (Grant No. 19-72-10138), the Icelandic Research Fund (Grant Nos. 184949 and 217750), the University of Iceland Research Fund (Grant No. 15673), and the Swedish Research Council (Grant No. 2020-05110) Peer Reviewed