Independence of the relaxation of a supercooled fluid of its microscopic dynamics: need for yet another extension of the mode-coupling theory

TL;DR

This study demonstrates that supercooled Brownian and Newtonian fluids exhibit similar relaxation behaviors near the mode-coupling transition, challenging existing theoretical models and suggesting the need for extended mode-coupling theory.

Contribution

The paper shows that Brownian and Newtonian supercooled fluids share similar relaxation dynamics, highlighting the necessity for extending mode-coupling theory to account for these findings.

Findings

Brownian and Newtonian systems show similar deviations from power-law behavior.

Dynamic events cut off the idealized mode-coupling transition in both systems.

Discussion of differences between simulation results and experimental data.

Abstract

Using Brownian Dynamics computer simulations we show that the relaxation of a supercooled Brownian system is qualitatively the same as that of a Newtonian system. In particular, near the so-called mode-coupling transition temperature, dynamic properties of the Brownian system exhibit the same deviations from power-law behavior as those of the Newtonian one. Thus, similar dynamical events cut off the idealized mode-coupling transition in Brownian and Newtonian systems. We discuss implications of this finding for extended mode-coupling theory. In addition, we point out and discuss the difference between our findings and experimental results, and present an alternative interpretation of some of our simulation data.