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

摘要

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.