Teixeira A W, Castillo-Sepúlveda S, Rizzi L G, Nunez A S, Troncoso R E, Altbir D, Fonseca J M, Carvalho-Santos V L
Departamento de Física, Universidade Federal de Viçosa, 36570-900, Viçosa, Brazil.
Facultad de Ingeniería, Universidad Autónoma de Chile, Av. Pedro de Valdivia 425, Providencia, Santiago, Chile.
J Phys Condens Matter. 2021 May 28;33(26). doi: 10.1088/1361-648X/abfb8c.
When the skyrmion dynamics beyond the particle-like description is considered, this topological structure can deform due to a self-induced field. In this work, we perform Monte Carlo simulations to characterize the skyrmion deformation during its steady movement. In the low-velocity regime, the deformation in the skyrmion shape is quantified by an effective inertial mass, which is related to the dissipative force. When skyrmions move faster, the large self-induced deformation triggers topological transitions. These transitions are characterized by the proliferation of skyrmions and a different total topological charge, which is obtained as a function of the skyrmion velocity. Our findings provide an alternative way to describe the dynamics of a skyrmion that accounts for the deformations of its structure. Furthermore, such motion-induced topological phase transitions make it possible to control the number of ferromagnetic skyrmions through velocity effects.
当考虑超越类粒子描述的斯格明子动力学时，这种拓扑结构会因自感场而发生形变。在这项工作中，我们进行蒙特卡罗模拟以表征斯格明子在稳定运动过程中的形变。在低速 regime 中，斯格明子形状的形变由一个有效惯性质量来量化，该质量与耗散力有关。当斯格明子移动得更快时，大的自感形变会引发拓扑转变。这些转变的特征是斯格明子的增殖和不同的总拓扑电荷，总拓扑电荷是作为斯格明子速度的函数而获得的。我们的发现提供了一种描述斯格明子动力学的替代方法，该方法考虑了其结构的形变。此外，这种运动诱导的拓扑相变使得通过速度效应来控制铁磁斯格明子的数量成为可能。
