Modulational instability and energy localization in anharmonic lattices at finite energy density
Modulational instability and energy localization in anharmonic lattices at finite energy density
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DOI：
10.1103/physrevb.61.299
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发表时间：
2000-01-01
影响因子：
3.7
通讯作者：
Lepri, S
中科院分区：
文献类型：
--
作者：
Kosevich, YA;Lepri, S
用连续介质理论研究了有限初始能量密度的经典非简谐振子链中布里渊区边界模的调制不稳定性引起的振动能局域化。我们描述的初始本地化阶段作为一个气体的信封孤子和解释他们的合并，最终导致一个单一的本地化对象包含宏观分数的晶格的总能量。解析地描述了孤子形成和合并的所有特征时间尺度与初始能量密度的关系。空间功率谱的计算和用于定量解释的数值结果。
The localization of vibrational energy, induced by the modulational instability of the Brillouin-zone-boundary mode in a chain of classical anharmonic oscillators with finite initial energy density, is studied within a continuum theory. We describe the initial localization stage as a gas of envelope solitons and explain their merging, eventually leading to a single localized object containing a macroscopic fraction of the total energy of the lattice. The initial-energy-density dependences of all characteristic time scales of the soliton formation and merging are described analytically. Spatial power spectra are computed and used for the quantitative explanation of the numerical results.