Semitopological solitons in planar ferromagnets
Semitopological solitons in planar ferromagnets
复制标题
DOI：
10.1088/0951-7715/12/2/008
复制
发表时间：
1999-03
期刊：
影响因子：
1.7
通讯作者：
N. Papanicolaou;P. Spathis
中科院分区：
文献类型：
--
作者：
N. Papanicolaou;P. Spathis
我们建立了二维平面铁磁体中有限能量孤立波的存在性，该铁磁体以任意小于磁振子速度c的恒定速度v作刚性运动。计算出的孤子的形状主要取决于v和c的相对大小。当v<<c时，孤子描述了一个在相对距离上进行Kelvin运动的分离的涡旋-反涡旋对。存在一个交叉速度v0，在该速度下，涡反涡特征消失，能量-动量弥散形成一个尖点。当v0<v<c时，孤子变成一个没有明显拓扑特征的团，在极限下解修正的KP方程。我们还简要地描述了一个类似的三维平面铁磁体中的涡环的计算。这些结果与解析已知的一维扭结一起提供了一组有趣的孤子，其物理意义尚待探讨。
We establish the existence of a finite-energy solitary wave in a two-dimensional planar ferromagnet which moves rigidly at any constant velocity v that is smaller than the magnon velocity c. The shape of the calculated soliton depends crucially on the relative magnitude of v and c. For v<<c, the soliton describes a widely separated vortex-antivortex pair undergoing Kelvin motion at a relative distance . There exists a crossover velocity v0 at which the vortex-antivortex character is lost and the energy-momentum dispersion develops a cusp. For v0<v<c, the soliton becomes a lump with no apparent topological features and solves the modified KP equation in the limit . We also describe briefly a similar calculation of a vortex ring in a three-dimensional planar ferromagnet. These results together with the analytically known one-dimensional kink provide an interesting set of semitopological solitons whose physical significance is yet to be explored.