各向异性对非对称薄膜中的自旋波的影响

The Effect of Uniaxial Anisotropy on the Spin Waves in an Asymmetrical Ferromagnetic Bilayer Film

采用界面重标度(IR)方法〔1〕,研究了非周期性边界条件下,双层非对称铁磁薄膜中自旋波的本征值问题,并计入体单轴各向异性,讨论了其对非对称铁磁薄膜中自旋波色散关系以及其波形的影响.结果表明:体单轴各向异性对非对称铁磁薄膜中的自旋波的影响很大,情况也较复杂.具体来说,随着两层薄膜中某一层的体各向异性常数的增加,体模和相应层内的禁闭模均有所变化(包括数目和数值),在整个变化过程中,光学-光学界面模的数目不变,本征模能量随DA(体各向异性)的增加而线性减小,而且,体单轴各向异性对各种自旋波本征模的波形影响也很大.

Under the nonperiodical boundary condition ,the eigenvalue problem of the spin-waves in an asymmetrical ferromagnetic bilayer film is investigated by the interface-rescaling approach.Meanwhile,the effect of uniaxial anisotropy on the dispersion relation and the wave form of the spin-waves is discussed.It is shown that the large changes of spin-waves take place when the effect of uniaxial anisotropy is taker into account.Concretely,with increasing of uniaxial anisotropy, there are changes of bulk-modes and confined-modes (including the change of numerical value and numbers)in sublayer A. Through the whole process,the number of the optical interface-modes is unchanged except the eigen-energy decreasing with the increasing of uniaxial anisotropy.Furthermore,there are large changes in the wave forms of spin-waves by considering the uniaxial anisotropy.