کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1897929 | 1044609 | 2008 | 8 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: The notion of persistence applied to breathers in thermal equilibrium The notion of persistence applied to breathers in thermal equilibrium](/preview/png/1897929.png)
We study the thermal equilibrium of nonlinear Klein–Gordon chains at the limit of small coupling (anticontinuum limit). We show that the persistence distribution associated to the local energy density is a useful tool to study the statistical distribution of the so-called thermal breathers, mainly when the equilibrium is characterized by long-lived pinned excitations; in that case, the distribution of persistence intervals turns out to be a power law. We demonstrate also that this generic behaviour has a counterpart in the power spectra, where the high-frequencies domains nicely collapse if properly rescaled. These results are also compared to nonlinear Klein–Gordon chains with a soft nonlinearity, for which the thermal breathers are rather mobile entities. Finally, we discuss the possibility of a breather-induced anomalous diffusion law, and show that despite a strong slowing down of the energy diffusion, there are numerical evidences for a normal asymptotic diffusion mechanism, but with exceptionally small diffusion coefficients.
Journal: Physica D: Nonlinear Phenomena - Volume 237, Issue 8, 15 June 2008, Pages 1013–1020