论文标题
寻找玻璃甘油中的加德纳过渡
Searching for the Gardner transition in glassy glycerol
论文作者
论文摘要
我们在标准分子玻璃玻璃甘油中寻找Gardner过渡，测量第三个谐波立方易感性$χ_3^{（3）} $从略低于通常的玻璃过渡温度降低至$ 10K $。根据平均场景图，如果由于出现Gardner阶段，玻璃内的局部运动变得高度相关，则$χ_3^{（3）} $，类似于动态的旋转玻璃敏感性，应在Gardnertner过渡温度$ t_g $上增加和差异。我们发现冷却后$ | χ_3^{（3）} | $减少了几个数量级，并且在制度中大致恒定$ 100K-10K $。我们通过假设低温物理学通过局部激发来描述我们的发现，从而通过旋转玻璃偶极偶极成对相互作用来描述低温物理学。我们的定量估计表明，自旋玻璃相互作用比局部随机场的贡献小二十至五十倍，从而使没有自旋玻璃gardner相的缺失合理化。这暗示了这样一个事实，即在标准分子玻璃中可能会抑制Gardner阶段，但它也提出了偏爱其在其他无定形固体中并通过更改制备方案的存在的方法。
We search for a Gardner transition in glassy glycerol, a standard molecular glass, measuring the third harmonics cubic susceptibility $χ_3^{(3)}$ from slightly below the usual glass transition temperature down to $10K$. According to the mean field picture, if local motion within the glass were becoming highly correlated due to the emergence of a Gardner phase then $χ_3^{(3)}$, which is analogous to the dynamical spin-glass susceptibility, should increase and diverge at the Gardner transition temperature $T_G$. We find instead that upon cooling $| χ_3^{(3)} |$ decreases by several orders of magnitude and becomes roughly constant in the regime $100K-10K$. We rationalize our findings by assuming that the low temperature physics is described by localized excitations weakly interacting via a spin-glass dipolar pairwise interaction in a random magnetic field. Our quantitative estimations show that the spin-glass interaction is twenty to fifty times smaller than the local random field contribution, thus rationalizing the absence of the spin-glass Gardner phase. This hints at the fact that a Gardner phase may be suppressed in standard molecular glasses, but it also suggests ways to favor its existence in other amorphous solids and by changing the preparation protocol.
