Nonlinear internal dynamics of the double-sine-Gordon soliton.
Nonlinear internal dynamics of the double-sine-Gordon soliton.
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双正弦戈登孤子的非线性内部动力学。
DOI：
10.1103/physrevb.36.6920
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发表时间：
1987
期刊：
影响因子：
--
通讯作者：
El
中科院分区：
文献类型：
--
作者：
Burdick;Willis;El
我们使用最近开发的集体变量哈密顿形式主义研究了双正弦戈登孤子的非线性内部动力学。我们在忽略连续声子场的近似中进行了这项研究。为了测试这种近似的有效性范围，我们使用双正弦戈登方程的分子动力学模拟进行了类似的研究。对结果进行详细比较后，模拟和哈密顿计算之间的内部模式的频率、振幅和空间形状非常一致。该协议在很宽的振幅范围内成立，从小振荡到高度非线性的大振荡区域。该协议支持这样的观点，即双正弦戈登孤子的内部振荡与声子连续体的耦合非常弱并且可以忽略不计，即使内部振荡是高度非线性的。
We have investigated the nonlinear internal dynamics of the double-sine-Gordon soliton using the recently developed collective-variable Hamiltonian formalism. We have carried out this investigation in the approximation in which the continuum phonon field is neglected. In order to test the range of validity of this approximation, we carried out a similar study using molecular-dynamics simulations of the double-sine-Gordon equation. A detailed comparison of the results yields an excellent agreement of the frequencies, amplitudes, and spatial shapes of the internal modes between the simulations and the Hamiltonian calculations. This agreement holds over a wide range of amplitude, from small oscillations to the highly nonlinear large-oscillation regime. The agreement supports the view that the coupling of the internal oscillations of the double-sine-Gordon soliton to the phonon continuum is extremely weak and can be neglected, even when the internal oscillation is highly nonlinear.