Spatial structure of quasilocalized vibrations in nearly jammed amorphous solids
Spatial structure of quasilocalized vibrations in nearly jammed amorphous solids
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DOI：
10.1103/physreve.98.060901
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发表时间：
2018-12-20
影响因子：
2.4
通讯作者：
Ikeda, Atsushi
中科院分区：
文献类型：
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作者：
Shimada, Masanari;Mizuno, Hideyuki;Ikeda, Atsushi
非晶态固体的低温性质被广泛认为是由低频准局域模控制的。然而，是什么支配着它们的空间结构和密度尚不清楚。我们研究这些问题的数值在非常大的系统的干扰过渡接近和压力p消失。我们发现，这些模式包括一个不稳定的核心和一个稳定的远场分量。核心的长度尺度以p（-1/4）发散，其特征体积以p（-1/2）发散。这些空间特征正是那些已知在弱配位材料的振动光谱中引起玻色子峰的反常模式。从这个对应关系中，我们推导出准局域模的密度必须遵循类似于ω（4）/p（2）的g（loc）（ω），这与以前的观察是一致的。因此，我们的分析表明，在一类非晶材料的准局域模式的性质。
The low-temperature properties of amorphous solids are widely believed to be controlled by the low-frequency quasilocalized modes. However, what governs their spatial structure and density is unclear. We study these questions numerically in very large systems as the jamming transition is approached and the pressure p vanishes. We find that these modes consist of an unstable core and a stable far-field component. The length scale of the core diverges as p(-1/4) and its characteristic volume diverges as p(-1/2). These spatial features are precisely those of the anomalous modes that are known to cause the boson peak in the vibrational spectra of weakly coordinated materials. From this correspondence, we deduce that the density of quasilocalized modes must follow g(loc) (omega) similar to omega(4)/p(2), which is in agreement with previous observations. Thus, our analysis demonstrates the nature of quasilocalized modes in a class of amorphous materials.