AI 中文总结
研究无Peierls-Nabarro势的离散φ⁴模型中扭结对声子的散射，发现散射特性强烈依赖晶格间距，强离散下出现显著反射，且扭结受负辐射压力加速。
AI 中文摘要
我们研究了小振幅波（称为声子）与初始静态扭结在无Peierls-Nabarro势的φ⁴模型特殊离散化中的相互作用。声子由局域谐波源产生，并从扭结一侧散射。通过计算整个声子频带上的透射和反射系数，我们证明了散射特性强烈依赖于晶格间距。在弱离散区域（h<1），扭结几乎透明，声子在其大部分频谱上透射。相反，对于强离散（h>1），即使相应的连续φ⁴扭结是无反射的，也会出现显著的反射。我们进一步表明，根据入射声子的频率，扭结经历负辐射压力，并在所有考虑的晶格间距下朝向入射声子加速，且这种效应在强离散下更强。扭结速度和能量转移的频率依赖性通过多普勒频移声子频率和声子群速度极值相关的共振来解释。我们的结果揭示，即使在静态Peierls-Nabarro势不存在的系统中，强晶格离散也能定性地改变声子-扭结相互作用。
英文摘要
We investigate the interaction of small-amplitude waves called phonons, with an initially static kink in an exceptional discretization of the $ϕ^4$ model that is free of the Peierls-Nabarro potential. Phonons are generated by a localized harmonic source and scattered from one side of the kink. By computing the transmission and reflection coefficients over the entire phonon band, we demonstrate that the scattering properties depend strongly on the lattice spacing. In the weak-discreteness regime ($h<1$), the kink is nearly transparent and phonons are transmitted through it over most of the phonon spectrum. In contrast, for strong discreteness ($h>1$), significant reflection emerges even though the corresponding continuum $ϕ^4$ kink is reflectionless. We further show that depending on the frequency of the incoming phonons, the kink experiences negative radiation pressure and is accelerated toward the incoming phonons for all lattice spacings considered, and this effect is much stronger for the strong discretness. The frequency dependence of the kink velocity and energy transfer is explained in terms of resonances associated with Doppler-shifted phonon frequencies and extrema of the phonon group velocity. Our results reveal that strong lattice discreteness can qualitatively modify phonon-kink interactions even in systems where the static Peierls-Nabarro potential is absent.
Comments12 pages, 7 figures
Journal refChaos, Solitons and Fractals 212 (2026) 119015
DOI：10.1016/j.chaos.2026.119015
