论文标题

塑料事件与跨空间尺寸堵塞包装中的局部结构的相关性

Correlation of plastic events with local structure in jammed packings across spatial dimensions

论文作者

Ridout, Sean A., Rocks, Jason W., Liu, Andrea J.

论文摘要

在堵塞的包装中,通常认为本地结构仅在特定政权中起重要作用。相对多余协调的标准偏差,$σ_z/ z_ \ mathrm {c} $,像$ 1/ \ sqrt {d} $一样衰减,以便本地结构在高空间维度中不起作用。此外,在任何固定尺寸$ d \ geq 2 $中,随着压力消失在接近无果断过渡的情况下,长度尺度有所不同,再次表明局部结构不足以描述响应。在这里,我们挑战以下假设:在这些情况下,本地结构无关紧要。在模拟Athermal,Athermal,Accistatic Shear下的堵塞包装中,我们使用机器学习来识别局部结构变量,柔软度,该变量与尺寸的重排相关,$ d = 2 $ d = 2 $至$ d = 5 $。我们发现,在所有研究的$ d $中,柔软度 - 甚至只是协调数量$ z $ - 都可以预测重排在各种压力上,一直以至于无障碍。该结果提供了直接的证据,表明局部结构可以在较高的空间维度中发挥作用。

In jammed packings, it is usually thought that local structure only plays a significant role in specific regimes. The standard deviation of the relative excess coordination, $σ_Z/ Z_\mathrm{c}$, decays like $1/\sqrt{d}$, so that local structure should play no role in high spatial dimensions. Furthermore, in any fixed dimension $d \geq 2$, there are diverging length scales as the pressure vanishes approaching the unjamming transition, again suggesting that local structure should not be sufficient to describe response. Here we challenge the assumption that local structure does not matter in these cases. In simulations of jammed packings under athermal, quasistatic shear, we use machine learning to identify a local structural variable, softness, that correlates with rearrangements in dimensions $d=2$ to $d=5$. We find that softness - and even just the coordination number $Z$ - are quite predictive of rearrangements over a wide range of pressures, all the way down to unjamming, in all $d$ studied. This result provides direct evidence that local structure can play a role in higher spatial dimensions.

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