非对称相互作用势对孤波散射过程中相移的影响  

The effect of asymmetric inter-particle interactions on spatial shift of solitary wave scattering

作　　者：张楠[1] 金涛[1] 

机构地区：[1]陕西师范大学物理学与信息技术学院,陕西西安710119

出　　处：《陕西师范大学学报（自然科学版）》2016年第1期34-38,共5页Journal of Shaanxi Normal University：Natural Science Edition

基　　金：国家自然科学基金(11147020);中央高校基本科研业务费专项资金(GK201102028)

摘　　要：研究了一维广义FPU-αβ晶格模型中微观粒子之间相互作用势的非对称性对孤波散射过程产生相移的影响,该系统存在两种拓扑孤波,Kink和Antikink。数值计算结果表明:随着非对称性强度增加,同种孤波散射所产生的相移减小,而异种孤波散射所产生的相移增大。为解释上述计算结果,在特殊孤波碰撞位形下将广义FPU-αβ晶格模型近似成具有非线性相互作用的两粒子系统,通过求解两粒子系统的动力学方程发现:在总能量确定的情况下,两粒子最大相对位移的绝对值随非对称性增加而减小;最大相对位移在扣除微观粒子两平衡位置间距后所得到的结果与数值计算得到孤波相移结果一致。The effect of asymmetry of interparticle interaction potential on the spatial shift of soli- tary wave scattering in one-dimensional generalized FPU-αβ lattice model are investigated. The system has two types of solitary wave, Kink and Antikink. The numerical result shows that with the increase of asymmetry the spatial shift decreases for the scattering between same types of soli- tary wave, while increases for the scattering between different types. To explain the above result, FPU-a~ lattice model as two particle system with nonlinear interaction under special collision con- figuration is approximately generalized. By solving the dynamical equation of two particle system, it can be found that the absolute value of maximum relative displacement between particles de- creases with the increase of asymmetry when the total energy is determined. Furthermore, when removing the spacing between two equilibrium position of the micro particle, the maximum rela- tive displacement is consistent with numerical result of spatial shift qualitatively.

关 键 词：孤波散射 相移 FPU—αβ晶格模型 非对称势 

分 类 号：O415.6[理学—理论物理]