Mean-squared Energy Difference for Exploring Potential Energy Landscapes of Supercooled Liquids

Abstract

By extending the concept of diffusion to the potential energy landscapes (PELs), we introduce the mean-squared energy difference (MSED) as a novel quantity to investigate the intrinsic properties of glass. MSED can provide a clear description of the "energy relaxation" process on a PEL. Through MSED analysis, we can obtain characteristic timescale similar to those from structure analysis, namely $\tau_\alpha^*$. We establish a connection between MSED and the properties of PELs, providing a concise and quantitative description of the PEL. We find that the roughness of the accessible PEL has changed significantly after the glass transition. And we also find that one of the PEL parameters is closely related to the Adam-Gibbs configurational entropy. The present research, which directly links the PEL to the relaxation process, provides avenues for further research of the glass.