Stretched Exponential Relaxation of Glasses at Low Temperature

Yingtian Yu, Mengyi Wang, Dawei Zhang, Bu Wang, Gaurav Sant, Mathieu Bauchy

Published 2015-03-25Version 1

The question of whether glass continues to relax at low temperature is of fundamental and practical interest. Here, we report a novel atomistic simulation method allowing us to directly access the long-term dynamics of glass relaxation at room temperature. We find that the potential energy relaxation follows a stretched exponential decay, with a stretching exponent $\beta = 3/5$, as predicted by Phillips' diffusion-trap model. Interestingly, volume relaxation is also found. However, it is not correlated to the energy relaxation, but is rather a manifestation of the mixed alkali effect.