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

TL;DR

This paper introduces the mean-squared energy difference (MSED) as a new method to analyze potential energy landscapes in supercooled liquids, revealing insights into energy relaxation and glass transition properties.

Contribution

It establishes a novel quantitative link between MSED and PEL characteristics, enhancing understanding of glass relaxation and transition mechanisms.

Findings

MSED describes the energy relaxation process on PELs.

The PEL roughness changes significantly after the glass transition.

One PEL parameter correlates with the Adam-Gibbs configurational entropy.

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.