Droplets and the configurational entropy crisis for random first order transitions

TL;DR

This paper investigates how droplet excitations influence the configurational entropy in glass transition theories, revealing that their impact varies with surface tension and explaining differences between structural glasses and spin-glass models.

Contribution

It provides a quantitative analysis of droplet effects on the configurational entropy and clarifies their role in the glass transition, especially in finite-range spin-glass models.

Findings

Droplet excitations can modify the glass transition temperature range.

Surface tension strongly affects the impact of droplet excitations.

Finite-range spin-glass models show significant entropy renormalization.

Abstract

We consider the effect of droplet excitations in the random first order transition theory of glasses on the configurational entropy. The contribution of these excitations is estimated both at and above the ideal glass transition temperature. The temperature range where such excitations could conceivably modify or `round-out' an underlying glass transition temperature is estimated, and found to depend strongly on the surface tension between locally metastable phases in the supercooled liquid. For real structural glasses this temperature range is found to be very narrow, consistent with the quantitative success of the theory. For certain finite-range spin-glass models, however, the surface tension is estimated to be significantly lower leading to much stronger entropy renormalizations, thus providing an explanation for the lack of a strict thermodynamic glass transition in simulations of these models.