Topological Aspects of Solitons in Ferromagnets

作     者：REN Ji-Rong WANG Ji-Biao LI Ran XU Dong-Hui DUAN Yi-Shi 

作者机构：Institute of Theoretical Physics Lanzhou University Lanzhou 730000 China 

出 版 物：《Communications in Theoretical Physics》 (理论物理通讯（英文版）)

年 卷 期：2008年第50卷第9期

页      面：777-780页

核心收录：

学科分类：080805[工学-电工理论与新技术] 080904[工学-电磁场与微波技术] 0808[工学-电气工程] 0809[工学-电子科学与技术（可授工学、理学学位）] 08[工学] 

基　　金：National Natural Science Foundation of China under Grant No.10275030 

主　　题：ferromagnets skyrmions vortex rings 

摘      要：Two kinds of topological soliton （skyrmion and magnetic vortex ring） in ferromagnets are studied. They have the common topological origin, a tensor Hαβ = n→·（δαn→×βδn→）, which describes the non-trivial distribution of local orientation of magnetization n→ at large distances in space. The topological stability of skyrmion is protected by the winding number. Knot-like topological defect as magnetic vortex rings is also studied. On the assumption that magnetic vortex rings are geometric lines, we present their δ-function distribution in ferromagnetic materials. Furthermore, it is briefly shown that Hopf invariant is a proper topological invariant to describe the topology of magnetic vortex rings.