Interaction of Soliton with an Impurity in Nonlinear Lattice
Interaction of Soliton with an Impurity in Nonlinear Lattice
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非线性晶格中孤子与杂质的相互作用
DOI：
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发表时间：
1981
期刊：
影响因子：
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通讯作者：
M. Toda
中科院分区：
文献类型：
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作者：
Shinsuke Watanabe;M. Toda
用计算机模拟方法研究了指数晶格中孤子与质量杂质的相互作用。我们特别研究了杂质对孤子振幅的影响。计算表明，在（A_{ ext{IN}}| D| lesssim 1），其中A IN表示入射孤子振幅，并且质量缺陷D由1- Q定义，如果Q表示杂质与宿主粒子的质量比。无论杂质是否比主粒子轻（Q1），该关系都成立.所得结果与基于逆方法的微扰理论定性一致。在轻杂质的情况下，在孤子通过杂质后，在杂质位置附近仍然存在一个局域模。局域模的频率随着模的振幅的增加而减小，与简单的模耦合理论定性一致。
Interaction of a soliton with a mass impurity in the exponential lattice has been studied by means of a computer simulation. We particularly investigate the decrease of the soliton amplitude due to an impurity. The present computation shows that the decrease of amplitude is proportional to ( A IN D ) 2 in the region of (A_{ ext{IN}}|D| lesssim 1), where A IN denotes the incident soliton amplitude and the mass defect D is defined by 1- Q , if Q denotes the mass ratio of the impurity to the host particle. The relation holds whether the impurity is lighter ( Q 1) than the host particle. The result agrees qualitatively with the perturbation theory based on the inverse method. In the case of a light impurity, there remains a localized mode near the impurity site, after a soliton has passed through the impurity. The frequency of the localized mode decreases as the amplitude of the mode increases, in a qualitative agreement with a simple mode-coupling theory.