Can the glass transition be explained without a growing static length scale?

TL;DR

This paper argues that the glass transition cannot be explained without a growing static length scale, and that the SWAP algorithm's acceleration of equilibration supports a local, static mechanism consistent with RFOT theory.

Contribution

It demonstrates that the SWAP algorithm's speedup aligns with RFOT theory, challenging claims that it disproves static length scale involvement in the glass transition.

Findings

SWAP accelerates equilibration in supercooled liquids.

Speedup is explained by delayed glassy dynamics onset.

Supports static, local mechanisms in glass transition.

Abstract

It was recently discovered that SWAP, a Monte Carlo algorithm that involves the exchange of pairs of particles of differing diameters, can dramatically accelerate the equilibration of simulated supercooled liquids in regimes where the normal dynamics is glassy. This spectacular effect was subsequently interpreted as direct evidence against a static, cooperative explanation of the glass transition such as the one offered by the random first-order transition (RFOT) theory. We review several empirical facts that support the opposite view, namely, that a local mechanism cannot explain the glass transition phenomenology. We explain the speedup induced by SWAP within the framework of the RFOT theory. We suggest that the efficiency of SWAP stems from a postponed onset of glassy dynamics, which allows the efficient exploration of configuration space even in the regime where the physical dynamics is dominated by activated events across free-energy barriers. We describe this effect in terms of `crumbling metastability' and use the example of nucleation to illustrate the possibility of circumventing free-energy barriers of thermodynamic origin by a change of the local dynamical rules.