Key aspects of glasses are controlled by the presence of excitations in which a group of particles can rearrange. Surprisingly, recent observations indicate that their density is dramatically reduced and their size decreases as the temperature of the supercooled liquid is lowered. Some theories predict these excitations to cause a gap in the spectrum of quasilocalized modes of the Hessian that grows upon cooling, while others predict a pseudogap $D_L\left(\omega \right)\sim {\omega }^{\alpha }$. To unify these views and observations, we generate glassy configurations of controlled gap magnitude ${\omega }_c$ at temperature $T=0$, using so-called breathing particles, and study how such gapped states respond to thermal fluctuations. We find that (i) the gap always fills up at finite $T$ with $D_L\left(\omega \right)\approx A_4\left(T\right){\omega }^4$ and $A_4\sim exp(-E_a/T)$ at low $T$, (ii) $E_a$ rapidly grows with ${\omega }_c$, in reasonable agreement with a simple scaling prediction $E_a\sim {\omega }_c^4$ and (iii) at larger ${\omega }_c$ excitations involve fewer particles, as we rationalize, and eventually become stringlike. We propose an interpretation of mean-field theories of the glass transition, in which the modes beyond the gap act as an excitation reservoir, from which a pseudogap distribution is populated with its magnitude rapidly decreasing at lower $T$. We discuss how this picture unifies the rarefaction as well as the decreasing size of excitations upon cooling, together with a stringlike relaxation occurring near the glass transition.

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玻璃中准局部激发的热起源

玻璃的关键方面是通过激发的存在来控制的，其中一组粒子可以重新排列。令人惊讶的是，最近的观察表明，随着过冷液体温度的降低，它们的密度显着降低，尺寸减小。一些理论预测这些激发会导致在冷却时生长的Hessian准局部化模式的光谱出现缺口，而另一些理论预测会出现伪间隙。$d_{\mathrm{大号}}（\omega ）〜{\omega }^{\alpha }$。为了统一这些观点和观察，我们生成了受控间隙幅度的玻璃状配置${\omega }_C$ 在温度下 $Ť=0$，使用所谓的呼吸粒子，并研究这种间隙状态如何响应热涨落。我们发现（i）差距总是在有限的情况下填满$Ť$ 与 $d_{\mathrm{大号}}（\omega ）\approx {\mathrm{一种}}_4（Ť）{\omega }^4$ 和 ${\mathrm{一种}}_4〜经验值（-{Ë}_{\mathrm{一种}}/Ť）$ 低 $Ť$，（ii） ${Ë}_{\mathrm{一种}}$ 迅速增长 ${\omega }_C$，并与简单的缩放预测合理地达成一致 ${Ë}_{\mathrm{一种}}〜{\omega }_C^4$ 及（iii）较大 ${\omega }_C$当我们合理化时，激发涉及的粒子更少，并最终变成弦状。我们提出了一种关于玻璃化转变的平均场理论的解释，在该理论中，间隙之外的模式起着激发储层的作用，从中填充伪间隙分布，其伪幅分布在较低温度下迅速减小。$Ť$。我们讨论了这张图片如何统一稀疏性以及冷却后减小的激发尺寸，以及在玻璃化转变附近发生的串状弛豫。