Supersonic discrete kink-solitons and sinusoidal patterns with "magic" wave number in anharmonic lattices

被引：37
作者：
Kosevich, YA
Khomeriki, R
Ruffo, S
机构：
[1] Univ Autonoma San Luis Potosi, Inst Invest Comunicac Opt, San Luis Potosi, SLP, Mexico
[2] Tbilisi State Univ, Dept Phys, GE-380028 Tbilisi, Georgia
[3] Univ Florence, Dipartimento Energet Sergio Stecco, I-50139 Florence, Italy
[4] Univ Florence, CSDC, I-50139 Florence, Italy
[5] INFM, Florence, Italy
[6] Ist Nazl Fis Nucl, I-50125 Florence, Italy
来源：
EUROPHYSICS LETTERS | 2004年 / 66卷 / 01期
关键词：
D O I：
10.1209/epl/i2003-10156-5
中图分类号：
O4 [物理学];
学科分类号：
0702 ;
摘要：
The sharp-pulse method is applied to Fermi-Pasta-Ulam (FPU) and Lennard-Jones (W) anharmonic lattices. Numerical simulations reveal the presence of high-energy strongly localized "discrete" kink-solitons (DK), which move with supersonic velocities that are proportional to kink amplitudes. For small amplitudes, the DKs of the FPU lattice reduce to the well-known "continuous" kink-soliton solutions of the modified Korteweg-de Vries equation. For high amplitudes, we obtain a consistent description of these DKs in terms of approximate solutions of the lattice equations that are obtained by restricting to a bounded support in space exact solutions with sinusoidal pattern characterized by the "magic" wave number k = 2pi/3. Relative displacement patterns, velocity vs. amplitude, dispersion relation and exponential tails found in numerical simulations are shown to agree very well with analytical predictions, for both FPU and LJ lattices.
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收藏
页码：21 / 27
页数：7
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