摘要
利用Landau Lifshitz方程 ,研究了具有非均匀交换各向异性的半无限大铁磁体的非线性表面自旋波理论。导出了部分钉扎纯交换铁磁介质的磁化强度所满足的边界条件和非线性表面自旋波的色散关系 ,并获得了自旋波振幅沿z方向驻波的一维非线性Schr dinger方程和包络振幅沿平面传播的二维非线性Schr dinger方程 ,结果表明铁磁体磁化强度的包络振幅随时空变化的性质是由二维非线性Schr dinger方程决定的。因此预言铁磁介质的表面非线性激发应是二维孤波的形式。对于弱非线性表面自旋波 ,对非线性Schr dinger方程存在孤子形式解的可能性作了讨论 .
The theory of nonlinear surface spin. waves in pure-exchange semi-infinite ferromagnetic media with inhomogeneous exchange anisotropy has been considered by using the Landau-Lifshitz equation. For partly pinned pure-exchange ferromagnet, the boundary condition for magnatization of this system is derived, and the nonlinear dispersion relation for these waves is obtained. The one-dimensional( stationary wave along the z-direction) and two-dimensional (2D) (travelling wave in the oxy plane) nonlinear Schrodinger equations which are satisfied by the spin-wave envelope amplitude of the magnetization, are derived. It is shown that the amplitude of the magnetization is determined by the 2D nonlinear Schrodinger equation. From this, we predict that the nonlinear excitation on the surface of magnetic materials should be of 2D soliton form. For weakly nonlinear spin waves, the possibility of soliton formation on the basis of 2D nonlinear Schrodinger equation has been discussed in detail.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2003年第11期2896-2900,共5页
Acta Physica Sinica
基金
中国科学院"百人计划"基金
国家自然科学基金 (批准号 :1983 5 0 5 0和 10 1740 2 7)资助的课题~~
