Pinning Susceptibility : A Novel Method to Study Growth of Amorphous Order in Glass-forming Liquids

TL;DR

This paper introduces a new, experimentally feasible correlation function to investigate the growth of amorphous order in supercooled liquids, validated through model systems and aligning with existing methods.

Contribution

A novel, simple correlation function for studying amorphous order growth, applicable in experiments and validated on model supercooled liquids.

Findings

Correlation length associated with amorphous order increases as liquids approach glass transition

New correlation function yields results consistent with traditional methods

Method enables experimental study of amorphous order growth in supercooled liquids

Abstract

Existence and growth of amorphous order in supercooled liquids approaching glass transition is a subject of intense research. Even after decades of work, there is still no clear consensus on the molecular mechanisms that lead to a rapid slowing down of liquid dynamics approaching this putative transition. The existence of a correlation length associated with amorphous order has recently been postulated and also been estimated using multi-point correlation functions which cannot be calculated easily in experiments. Thus the study of growing amorphous order remains mostly restricted to systems like colloidal glasses and simulations of model glass-forming liquids. In this Letter, we propose an experimentally realizable yet simple correlation function to study the growth of amorphous order. We then demonstrate the validity of this approach for a few well-studied model supercooled liquids and obtain results which are consistent with other conventional methods.