arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2002.10868cond-mat.stat-mechmath-phmath.MP
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经典声子场中的预热化:声子数的缓慢弛豫

Pre-thermalization in a classical phonon field: slow relaxation of the number of phonons

François Huveneers, Jani Lukkarinen

摘要:

我们研究了在经典声子场中出现的一个非常长的预热平台,这里是一个具有现场钉扎的谐波链。可积性被强度为$λ$的弱非调和在位势打破。在小$λ$极限下,用动力学理论描述了平移不变初态的平衡过程。然而,当声子带变窄时,我们发现声子的(非保守)数量在比动力学更长的时间尺度上弛豫。我们建立严格的界限上的弛豫时间,并制定了一个理论,产生精确的预测的耗散率在限制$λ\to 0$。我们比较了理论预测与数据从分子动力学模拟,发现很好的协议。我们的工作显示了经典系统如何表现出乍一看似乎需要量子化的现象。

英文摘要:

We investigate the emergence of an astonishingly long pre-thermal plateau in a classical phonon field, here a harmonic chain with on-site pinning. Integrability is broken by a weak anharmonic on-site potential with strength $λ$. In the small $λ$ limit, the approach to equilibrium of a translation invariant initial state is described by kinetic theory. However, when the phonon band becomes narrow, we find that the (non-conserved) number of phonons relaxes on much longer time scales than kinetic. We establish rigorous bounds on the relaxation time, and develop a theory that yields exact predictions for the dissipation rate in the limit $λ\to 0$. We compare the theoretical predictions with data from molecular dynamics simulations and find good agreement. Our work shows how classical systems may exhibit phenomena which at the first glance appear to require quantization.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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