Self-organized, noise-free escape of a coupled nonlinear oscillator chain
Self-organized, noise-free escape of a coupled nonlinear oscillator chain
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耦合非线性振荡器链的自组织、无噪声逃逸
DOI：
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发表时间：
2007
期刊：
影响因子：
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通讯作者：
P. Hänggi
中科院分区：
文献类型：
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作者：
D. Hennig;L. Schimansky;P. Hänggi
我们考虑了一系列简谐耦合单元链在立方势垒上从亚稳态的自组织逃逸。潜在的动力是保守的，纯粹是决定论的。足够的总能量的供应将链转变为非线性区域，从该区域开始，几乎均匀的晶格构型变得不稳定，从而产生具有强烈局域化能量的重新分布。一种自发出现的局域化模式成长为临界核。一旦通过这个过渡态，非线性链就执行一个集体的、确定性的逃逸事件。令人惊讶的是，我们发现这种无噪声的集体非线性势垒穿越事件与持续碰撞热噪声辅助的事件相比，产生的平均逃逸时间大大减少。链条逃逸率的这种有益的增强通常发生在链条中每单位供应的平均能量与势垒能量之间的比率采用小值的时候。
We consider the self-organized escape of a chain of harmonically coupled units from a metastable state over a cubic potential barrier. The underlying dynamics is conservative and purely deterministic. The supply of a sufficient total energy transforms the chain into the nonlinear regime from which an initially, nearly uniform lattice configuration becomes unstable, yielding a redistribution with a strong localization of energy. A spontaneously emerging localized mode grows into the critical nucleus. Upon passing this transition state, the nonlinear chain performs a collective, deterministic escape event. Surprisingly, we find that such noise-free, collective nonlinear barrier crossing events yield a drastically diminished average escape time as compared to the one that is assisted by continuously impacting thermal noise. This beneficial enhancement of the rate of escape for the chain typically occurs whenever the ratio between the average energy supplied per unit in the chain and the potential barrier energy assumes small values.