Searching for the Gardner Transition in Glassy Glycerol

We search for a Gardner transition in glassy glycerol, a standard molecular glass, measuring the third harmonics cubic susceptibility chi((3))(3) from slightly below the usual glass transition temperature down to 10 K. 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 chi((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 vertical bar chi((3))(3)vertical bar decreases by several orders of magnitude and becomes roughly constant in the regime 100 - 10 K. 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.

Automated summary

The study revealed the absence of a Gardner phase transition in glassy glycerol, suggesting that standard molecular glasses may suppress its existence. Instead, a specific localized excitation pattern was observed at low temperatures.